Gendell, M., & Hellegers, A. E. (1973). The influence of the changes in maternal age, birth order, and color on the changing perinatal mortality, Baltimore, 1961-66.

Gendell, Murray, و André E. Hellegers. The Influence of the Changes in Maternal Age, Birth Order, and Color On the Changing Perinatal Mortality, Baltimore, 1961-66. 1973.

Gendell, Murray, و André E. Hellegers. The Influence of the Changes in Maternal Age, Birth Order, and Color On the Changing Perinatal Mortality, Baltimore, 1961-66. 1973.