1. ALTMAN, P.L. & DITTMER, DOROTHY, S. 1971. Biological Handbooks, Respiration and Circulation, p.26. Federation of American Societies for Experimental Biology, Bethesda.
2. BEDFORD, T. 1946. Environmental warmth and its measurement. H.M.S.O., London.
3. BENEDICT, EG. 1936. The physiology of the elephant. Carnegie Institution of Washington, Washington.
4. BRODY, S. 1945. Bioenergetics and growth. Reinhold Publishing Corporation, New York.
5. CENA, K. 1974. Radiative heat loss from animals and man. In: Heat loss from animals and man, (ed.) Monteith, J.L. and Mount, L.E. pp.33–58, Butterworths, London.