How central is the alliance in psychotherapy? A multilevel longitudinal meta-analysis
Journal of Counseling Psychology (2012) - Comment
pubmed: 21988681  doi: 10.1037/a0025749  issn: 0022-0167  issn: 1939-2168 

Christoph Flückiger, A. C. Del Re, Bruce E. Wampold, Dianne Symonds, Adam O. Horvath