Bączek, Grażyna, Anita Pietrzak, and Urszula Tataj–Puzyna. “Perception of Natural Methods of Recognition of Fertility by Students of Medical, Technical and Catholic Universities”. Quarterly Journal Fides et Ratio 35, no. 3 (September 30, 2018): 70–91. Accessed August 17, 2025. https://fidesetratio.com.pl/ojs/index.php/FetR/article/view/520.