Schweickert, R. ., Z. Xi, C. Viau-Quesnel, and X. Zheng. “Power Law Distribution of Frequencies of Characters in Dreams Explained by Random Walk on Semantic Network”. International Journal of Dream Research, vol. 13, no. 2, Sept. 2020, pp. 192-01, doi:10.11588/ijodr.2020.2.71370.