On the frontier of adulthood : theory, research, and public policy / Richard A. Settersten, Jr., Frank F. Furstenberg, Jr., and Rubén G. Rumbaut, editors
Chicago : University of Chicago Press, c2005

3rd Floor Books HQ799.5 .O6 2005

Measurement of Subjective Age Identity Variables
Shanahan, Porfeli, Mortimer, and Erickson
p. 252