Excerpts from some excellent research papers can be selected below:
A 1994 French study of contraceptive underwear (in English).
Sperm production can be stopped for months using hot baths.
A long report of using hot baths for contrception in India.
A short report of using hot baths for contrception in India.
A 1997 French study of the effect of body heat on spermatogenesis (in English).
A review of research on contraceptive suspensories.
Three new methods for male contraception.
Microscope equipment specifically designed for sperm count measurement.