Gollwitzer, P. M., Bayer, U., Scherer, M., & Seifert, A. E. (1999). A motivational-volitional perspective on identity development. In J. Brandtstaetter & R. M. Lerner (Eds.), Action and self-development: Theory and research through the life-span (pp. 283-314). Thousand Oaks, CA: Sage.