Template:Ref-PattenKramer1933
From Embryology
Patten BM. and Kramer TC. The initiation of contraction in the embryonic chick heart. (1933) Amer. J Anat. 53: 349-375.
Patten BM. and Kramer TC. The initiation of contraction in the embryonic chick heart. (1933) Amer. J Anat. 53: 349-375.