diff --git a/README.md b/README.md
index d957f73..dee34b8 100644
--- a/README.md
+++ b/README.md
@@ -1,54 +1,54 @@
 # MintPy-tutorial
 
 [![Language](https://img.shields.io/badge/python-3.5%2B-blue.svg)](https://www.python.org/)
-[![License](https://img.shields.io/badge/license-GPLv3-yellow.svg)](https://github.com/insarlab/MintPy-tutorial/blob/master/LICENSE)
-[![render](https://img.shields.io/badge/render-nbviewer-orange.svg)](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/tree/master/)
+[![License](https://img.shields.io/badge/license-GPLv3-yellow.svg)](https://github.com/insarlab/MintPy-tutorial/blob/main/LICENSE)
+[![render](https://img.shields.io/badge/render-nbviewer-orange.svg)](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/tree/main/)
 [![Citation](https://img.shields.io/badge/doi-10.1016%2Fj.cageo.2019.104331-blue)](https://doi.org/10.1016/j.cageo.2019.104331)
 
 MintPy-tutorials contains the documentations for the [MintPy repo](https://github.com/insarlab/MintPy), mainly in Jupyter Notebook.
 
-## Contents ([nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/tree/master/))
+## Contents ([nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/tree/main/))
 
 1. Small baseline time series analysis with `smallbaselineApp`. This tutorial walks through the various processing steps of InSAR time series analysis using MintPy.     
 
-   - ISCE/topsStack + MintPy (Sentinel-1 on Fernandina volcano, Galápagos): [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/smallbaselineApp.ipynb)
-   - ARIA + MintPy (Sentinel-1 on San Francisco): [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/smallbaselineApp_aria.ipynb)
+   - ISCE/topsStack + MintPy (Sentinel-1 on Fernandina volcano, Galápagos): [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/smallbaselineApp.ipynb)
+   - ARIA + MintPy (Sentinel-1 on San Francisco): [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/smallbaselineApp_aria.ipynb)
 
 2. Visualizations   
 
-   - Interactive time-series with [tsview](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/visualization/tsview.ipynb)
-   - Interactive coherence matrix with [plot_coherence_matrix](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/visualization/plot_coherence_matrix.ipynb)
-   - Interactive transection with [plot_transection](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/visualization/plot_transection.ipynb)
+   - Interactive time-series with [tsview](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/visualization/tsview.ipynb)
+   - Interactive coherence matrix with [plot_coherence_matrix](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/visualization/plot_coherence_matrix.ipynb)
+   - Interactive transection with [plot_transection](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/visualization/plot_transection.ipynb)
    - Google Earth [doc](https://mintpy.readthedocs.io/en/latest/google_earth/)
 
 3. Read / write data files
 
-   - Read GMT *.grd file: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/io/read_gmt_grd.ipynb)
-   - Read / save time-series HDF5 file into text file: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/io/save_data2text.ipynb)
-   - Read / plot displacement time-series of one pixel: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/plot_displacement_timeseries.ipynb)
+   - Read GMT *.grd file: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/io/read_gmt_grd.ipynb)
+   - Read / save time-series HDF5 file into text file: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/io/save_data2text.ipynb)
+   - Read / plot displacement time-series of one pixel: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/plot_displacement_timeseries.ipynb)
    - Read HDF5 files in Matlab: [m file](./io/read_hdf5.m)
 
 4. Custom applications. List of examples of how to build customized application using mintpy modules or to build processing recipe using mintpy scripts.     
 
-   - Calculate multilook number for InSAR processing with ISCE: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/calc_multilook_number.ipynb)
-   - Create water mask in radar coordinates: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/water_mask.ipynb)
-   - Tropospheric delay correction using GACOS products: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/tropo_gacos.ipynb)
-   - Post-processing of single interferogram after ISCE/stripmapApp: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/stripmapApp_postprocessing.ipynb)
-   - Geo / radar coordinates conversion: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/coordinate_conversion.ipynb)
-   - Plot GPS as quiver on top of InSAR data: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/plot_gps_quiver.ipynb)
-   - Average velocity estimation demonstration: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/master/applications/timeseries2velocity.ipynb)
+   - Calculate multilook number for InSAR processing with ISCE: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/calc_multilook_number.ipynb)
+   - Create water mask in radar coordinates: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/water_mask.ipynb)
+   - Tropospheric delay correction using GACOS products: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/tropo_gacos.ipynb)
+   - Post-processing of single interferogram after ISCE/stripmapApp: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/stripmapApp_postprocessing.ipynb)
+   - Geo / radar coordinates conversion: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/coordinate_conversion.ipynb)
+   - Plot GPS as quiver on top of InSAR data: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/plot_gps_quiver.ipynb)
+   - Average velocity estimation demonstration: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/blob/main/applications/timeseries2velocity.ipynb)
 
 ## Useful links from external repositories ##
 
 1. Single interferogram processing with [ISCE2](https://github.com/isce-framework/isce2-docs/tree/master/Notebooks)
 
-   - Sentinel-1 TOPS mode SAR data with [topsApp](https://nbviewer.jupyter.org/github/isce-framework/isce2-docs/blob/master/Notebooks/TOPS/Tops.ipynb)
-   - StripMap mode SAR data with [stripmapApp](https://nbviewer.jupyter.org/github/isce-framework/isce2-docs/blob/master/Notebooks/Stripmap/stripmapApp.ipynb)
+   - Sentinel-1 TOPS mode SAR data with [topsApp](https://nbviewer.jupyter.org/github/isce-framework/isce2-docs/blob/master/Notebooks/UNAVCO_2020/TOPS/topsApp.ipynb)
+   - StripMap mode SAR data with [stripmapApp](https://nbviewer.jupyter.org/github/isce-framework/isce2-docs/blob/master/Notebooks/UNAVCO_2020/Stripmap/stripmapApp.ipynb)
 
-2. Stack of interferograms processing with [ISCE2 stack processors](https://github.com/isce-framework/isce2/blob/master/contrib/stack/README.md)
+2. Stack of interferograms processing with [ISCE2 stack processors](https://github.com/isce-framework/isce2/blob/main/contrib/stack/README.md)
 
-   - Sentinel-1 TOPS mode SAR data with [topsStack](https://github.com/isce-framework/isce2/blob/master/contrib/stack/topsStack/README.md)
-   - StripMap mode SAR data with [stripmapStack](https://github.com/isce-framework/isce2/blob/master/contrib/stack/stripmapStack/README.md)
+   - Sentinel-1 TOPS mode SAR data with [topsStack](https://github.com/isce-framework/isce2/blob/main/contrib/stack/topsStack/README.md)
+   - StripMap mode SAR data with [stripmapStack](https://github.com/isce-framework/isce2/blob/main/contrib/stack/stripmapStack/README.md)
 
 3. Manipulate ARIA standard InSAR products with [ARIA-tools](https://github.com/aria-tools/ARIA-tools-docs)
 
diff --git a/simulations/README.md b/simulations/README.md
index 497d8b8..236eb00 100644
--- a/simulations/README.md
+++ b/simulations/README.md
@@ -1,5 +1,5 @@
-## Simulation of 3D phase time-series based on [`mintpy.simulation`](https://github.com/insarlab/MintPy/tree/master/mintpy/simulation) ##
+## Simulation of 3D phase time-series based on [`mintpy.simulation`](https://github.com/insarlab/MintPy/tree/main/mintpy/simulation) ##
 
 🚨 **This toolbox is in alpha stage and undergoing rapid development.** 🚨
 
-An example of simulating displacement, tropospheric delays, topographic residuals and phase ramps to construct a 3D raw phase time-series: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/tree/master/simulations/). Handy tools for algorithm developers.
+An example of simulating displacement, tropospheric delays, topographic residuals and phase ramps to construct a 3D raw phase time-series: [nbviewer](https://nbviewer.jupyter.org/github/insarlab/MintPy-tutorial/tree/main/simulations/). Handy tools for algorithm developers.