Protective Factors for Posttraumatic Stress Disorder Symptoms in a Prospective Study of Police Officers Publication Type: Journal Article Authors: Chengmei Yuan; Zhen Wang; Sabra S. Inslichi; Shannon E. McCaslin; Thomas J. Metzler; Clare Henn-Haase; Brigitte A. Apfel; Huiqi Tong; Thomas C. Neylan; Yiru Fang; Charles R. Marmard Source: Psychiatry Research, Volume 188, Issue 1, p.45–50 (2012)