Template:Ref-HertigRock1939
From Embryology
Hertig AT. and Rock J. On a complete normal 12-day human ovum of the pre-villous stage. (1939) (Abst.) Anat. Rec. 73: 26.
Hertig AT. and Rock J. On a complete normal 12-day human ovum of the pre-villous stage. (1939) (Abst.) Anat. Rec. 73: 26.