T. d’Ansembourg. Cessez d’être gentil, soyez vrai! – Les Editions de l’Homme, 2003.

М. Bennett, С. Lengacher. Humor and laughter may influence health. Evidence-Based Complementary and Alternative Medicine, 2007; S. Sakuragi, Y. Sugiyama, K. Takeuchi. Effects of laughing and weeping on mood and heart rate variability. Journal of Physiological Anthropology and Applied Human Science. Vol. 21. № 3.