Public Domain Aeronautical Software (PDAS)  

The archive file turbsf.zip contains the files:

readme.txt general description
sftab.f90 sample program containing the function
sftab.out output from the sample program
turbsf.f90 the subroutine by itself
turbsf.cpp the same subroutine, coded in C++
Public Domain Aeronautical Software (PDAS)