Schou-Bredal, Inger, Tore Bonsaksen, Trond Heir, Laila Skogstad, Anners Lerdal, Tine Grimholt, i Øivind Ekeberg. „Optimists Report Fewer Physical and Mental Health Conditions Than Pessimists in the General Norwegian Population”. Health Psychology Report 7, no. 1 (marzec 7, 2019): 9–18. Udostępniono listopad 24, 2024. https://czasopisma.bg.ug.edu.pl/index.php/HPR/article/view/7920.