"Journal of Perinatal Medicine - Official Journal of the WAPM", 8.4 (1980): 171-217. Retrieved 21 May. 2013, from http://www.degruyter.com/view/j/jpme.1980.8.issue-4/issue-files/jpme.1980.8.issue-4.xml

Journal of Perinatal Medicine - Official Journal of the WAPM (1980), 8(4), pp. 171-217. Retrieved 21 May. 2013, from http://www.degruyter.com/view/j/jpme.1980.8.issue-4/issue-files/jpme.1980.8.issue-4.xml

Journal of Perinatal Medicine - Official Journal of the WAPM. 1980. 8(4): 171-217. Retrieved 21 May. 2013, from http://www.degruyter.com/view/j/jpme.1980.8.issue-4/issue-files/jpme.1980.8.issue-4.xml