C link to FORTRAN 77 routine 662 of reference [1] for the inversion of Laplace transforms. See also the accompanying reference [2].
[1] B. S. Garbow, G. Giunta, J. N. Lyness, A. Murli, Software for an Implementation of Weeks’ Method for the Inverse Laplace Transform, ACM Trans. Math. Softw. 14 (1988) 163–170.
[2] B. S. Garbow, G. Giunta, J. N. Lyness, A. Murli, Algorithm 662: A Fortran Software Package for the Numerical Inversion of the Laplace Transform Based on Weeks’ Method, ACM Trans. Math. Softw. 14 (1988) 171–176.