Zunker, M., Althoff, H.K., Apel, J., Lässig, H.S., Schültke, L. and Schredl, M. 2015. Comparing questionnaire and diary measures for eliciting nightmare frequency. International Journal of Dream Research. 8, 2 (Nov. 2015), 129–134. DOI:https://doi.org/10.11588/ijodr.2015.2.23395.