HP-UX Floating-Point Guide

124 Chapter 4
HP-UX Math Libraries on HP 9000 Systems
Calling C Library Functions from Fortran
You can compile and run the program as follows:
$ f90 bessel.f -lm
bessel.f
program BESSEL
16 Lines Compiled
$ ./a.out
Bessel of 1.0 is .765197686557967