Strasburger, Aleksander, i Andrzej Zembrzuski. 2011. „On Application of Newton’s Method to Solve Optimization Problems in the Consumer Theory. Expansion’s Paths and Engel Curves”. Metody Ilościowe W Badaniach Ekonomicznych 12 (1):135-46. https://qme.sggw.edu.pl/article/view/3104.