* Knowlton, Charles, (1832), "The Fruits of Philosophy, or the Private Companion of Young Married People", 1891 Bradlaugh-Besant Reprint (Google books)* Owen, Robert Dale (1831), "Moral Physiology, or A Brief and Plain Treatise on the Population Question", 1842 edition, (Google books)* Sanger, Margaret (1911), "What Every Mother Should Know", Based on a series of articles Sanger published in 1911 in the New York Call, which were, in turn, based on a set of lectures Sanger gave to groups of Socialist party women in 1910–11.
* Knowlton, Charles, (1832), "The Fruits of Philosophy, or the Private Companion of Young Married People", 1891 Bradlaugh-Besant Reprint (Google books)* Owen, Robert Dale (1831), "Moral Physiology, or A Brief and Plain Treatise on the Population Question", 1842 edition, (Google books)* Sanger, Margaret (1911), "What Every Mother Should Know", Based on a series of articles Sanger published in 1911 in the New York Call, which were, in turn, based on a set of lectures Sanger gave to groups of Socialist party women in 1910–11.