APA

Pryor Frederic L, Schaffer David L, . (1999). Who's not working and why : Employment, cognitive skills, wages, and the changing US labor market. Cambridge: Cambridge University Press.

Chicago

Pryor Frederic L, Schaffer David L, . 1999. Who's not working and why : Employment, cognitive skills, wages, and the changing US labor market. Cambridge: Cambridge University Press.

Harvard

Pryor Frederic L, Schaffer David L, . (1999). Who's not working and why : Employment, cognitive skills, wages, and the changing US labor market. Cambridge: Cambridge University Press.

MLA

Pryor Frederic L, Schaffer David L, . Who's not working and why : Employment, cognitive skills, wages, and the changing US labor market. Cambridge: Cambridge University Press. 1999.