1. Energy and Protein Requirements, FAO Nutr. Meetings Rept. Series No. 52, who Tech. Rept. Series No. 522, 1973.
2. Caloric cost of normal pregnancy;Emerson;Obstet. Gynecol.,1972
3. Hytten, F.E., and Leitch, J.: The Physiology of Human Pregnancy. Oxford: Blackwell Scientific Publications, 1964, p. 415.