Chehelcheraghi M, van Leeuwen C, Steur E, Nakatani C (2017) A
neural mass model of cross frequency coupling. PLoS One
12:e0173776

is available from a link in the above paper:
https://zenodo.org/record/248829

To run:

After downloading and expanding the archive type "Main" to start
Main.m on the matlab prompt.  After a few minutes graphs similar to
figure 6 in the paper appears: