X spermatozoa larger than Y in 1973.
Geraedts
J P
JP
D002469:Cell Separation / Q000266:history; D049673:History, 20th Century; D006801:Humans; D008297:Male; D012106:Research / Q000266:history; D012743:Sex Preselection / Q000379:methods; D013094:Spermatozoa / Q000648:ultrastructure*; D014960:X Chromosome; D014998:Y Chromosome