If you use FMC, and consider it appropriate, you can acknowledge it by citing one of the the following references:
Álvarez-Gómez, J. A. (2019). FMC—Earthquake focal mechanisms data management, cluster and classification. SoftwareX, 9, 299-307.
You should cite the SoftwareX paper if you are using the last version of the program with clustering and several plot cutomization options.
Álvarez-Gómez, J.A. (2014) FMC: a one-liner Python program to manage, classify and plot focal mechanisms. Geophysical Research Abstracts, Vol. 16, EGU2014-10887.
