1. Boyd, W C. 1939. Tab Biol, 17.
2. Chalmers, J N M, Ikin, Elizabeth W, and Mourant, A E. 1949. Am J Phys Anthrop, N.S., 7, 529–544.
3. Kayssi, A I. 1949. Am J Phys Anthrop, N.S., 7, 549–551.
4. Mourant, A E. 1949. Nature, 163, 913.
5. Prasad, C H, Ikin, Elizabeth W, and Mourant, A E. 1949. Am J Phys Anthrop, N.S., 7, 553–558.