5DeAngelo, Linda Elizabeth. "Auditor size and audit quality." Journal of accounting and economics 3.3 (1981): 183-199.
6LIM, CHEE YEOW, and HUN TONG TAN. "Non-audit Service Fees and Audit Quality: The Impact of Auditor Specialization." Journal of accounting research 46.1 (2008): 199-246.
7Craswell, Alien, Donald J. Stokes, and Janet Laughton. "Auditor independence and fee dependence. " Journal of Accotmting and Economics 33.2 (2002): 253-275.