Lewandowski, S. “Zur Bestimmung Eines Familienpolitischen Grenznutzens: Eine Kritik Am 5. Familienbericht: Determination of a Marginal Family Policy Utility - a Criticism of the 5th Family Report”. Journal of Family Research, vol. 8, no. 2, Sept. 1996, pp. p. 43-51, https://ubp.uni-bamberg.de/jfr/index.php/jfr/article/view/560.