Flückiger C, Rubel J, Del Re AC, Horvath AO, Wampold BE, Crits-Christoph P, Atzil-Slonim D, Compare A, Falkenström F, Ekeblad A, et al. The reciprocal relationship between alliance and early treatment symptoms: A two-stage individual participant data meta-analysis. Journal of Consulting and Clinical Psychology. 2020;88 (9) :829-843.