Mantzios, Michail, Hafsah Hussain, Amirah Hussain, Helen Egan, i Paraic Scanlon. 2019. „Adult Colouring: the Effect of App-Based Vs. Pen-and-Paper Colouring on Mindfulness and Anxiety”. Health Psychology Report 7 (4):286-95. https://czasopisma.bg.ug.edu.pl/index.php/HPR/article/view/7948.