Engel, C., Meisner, C., Wittorf, A., Wölwer, W., Wiedemann, G., Ring, C., Muche, R. and Klingberg, S. 2013. Longitudinal Data Analysis of Symptom Score Trajectories Using Linear Mixed Models in a Clinical Trial. International Journal of Statistics in Medical Research. 2, 4 (Oct. 2013), 305–315. DOI:https://doi.org/10.6000/1929-6029.2013.02.04.7.