Schredl, Michael, Louisa Holyba, Tina Köllmer, Jessica Körfer, and Annika Proß. “Nightmare Distress, Nightmare Frequency, and Beliefs about Nightmares”. International Journal of Dream Research 12, no. 2 (October 1, 2019): 60-66. Accessed February 17, 2020. https://journals.ub.uni-heidelberg.de/index.php/IJoDR/article/view/62531.