Module imslf90

Hi all, I am newbie in fortran. I got an old code to solve vibration problem from my lab mate. in the second row of code I saw USE imlsf90. When I tried to run on plato FTN95, it was not working because of this module not available.

where I can find similar module like this

thank you in advance

Sounds like the IMSL maths library - a commercial package that would need to be installed separately on your machine.