1. Parkes AS. Preservation of human spermatozoa at low temperatures. Br Med J. 1945;2:212–3.
2. Sherman JK, Buge RG. Observations on preservation of human spermatozoa at low temperatures. Proc Soc Exp Biol Med. 1953;82:686–8.
3. Hammerstedt RH, Graham JK, Nolan JP. Cryopreservation of mammalian sperm; what we ask them to survive. J Androl. 1990;11:73–88.
4. Spallanzani L, Opuscoli di Fisca, Amimale, e Vegetgabile, Opuscolo II. Osservazioni, e Speriencze inotrno ai Vermicelli Spermatici dell’Uomo e degli Amimali. Modena; 1776.
5. Montegazza J. Fisologia sullo sperma umano. Rendic reale Instit Lomb. 1866;3:183–5.