Textbooks of obstetrics and midwifery (1850-1907)
36. Churchill F (1850) On the Theory and Practice of Midwifery. London: Henry
Renshaw.
37. Swayne JG (1856) Obstetric Aphorisms: For the use of students
commencing midwifery practice. London: John Churchill.
38. Lusk WT (1882) The Science and Art of Midwifery.  New York: D Appleton
and Company, pp214-215
39. Leishman W (1888) A System of Midwifery Glasgow James MacLehose &
Sons.
40. Corney, BG (1899) Instructions with reference to the treatment of the
umbilical cord.
41. King AFA (1907) A Manual of Obstetrics, Tenth Edition.  Lea Brothers &
Co., Philadelphia and New York
http://placentalrespiration.net/
From the bibliography for
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