1. 1930 Piersol's Human Anatomy, p. 522, 9th ed., edited by J. B. Lippincott Co., Philadelphia.
2. 1930 Piersol's Human Anatomy, p. 522, 9th ed., cited by J. B. Lippincott Co., Philadelphia.
3. 1930 Piersol's Human Anatomy, p. 522, 9th ed., edited by J. B. Lippincott Co., Philadelphia.
4. 1930 Piersol's Human Anatomy, p. 517, 9th ed., edited by J. B. Lippincott Co., Philadelphia.