title: Effect of sperm concentration in the zona-free hamster ova penetration assay.
mesh_terms: D000818:Animals; D006224:Cricetinae; D005260:Female; D005306:Fertilization; D006801:Humans; D008297:Male; D013076:Sperm Count; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions