1. “Measurement of Subjective Responses”;Beecher,1959
2. “Recent Advances in Obstetrics and Gynaecology”;Bourne,1932
3. “Natural Childbirth”;Dick-Read,1933
4. “Physiotherapy in Obstetrics and Gynaecology”;Heardman,1951
5. Marshall, Allan R. (1928), “Report on Maternal Mortality and Morbidity in the State of Victoria, Australia”.