Induction of superovulation in women undergoing assisted reproductive techniques: recombinant human follicle stimulating hormone (r-hFSH; Gonal-F®) versus highly purified urinary FSH (Metrodin HP®). - Lenton,E.; Soltan,A.; Hewitt,J.; Thomson,A.; Davies,W.; Ashraf,N.; Sharma,V.; Jenner,L.; Ledger,W.; McVeigh,E. (Hum Reprod, 2000)