APA

Yorkey R. C., . (1970). Study skills : for students of english as a second language. Estados Unidos: McGraw-Hill Interamericana.

Chicago

Yorkey Richar C, . 1970. Study skills : for students of english as a second language. Estados Unidos: McGraw-Hill Interamericana.

Harvard

Yorkey R. C., . (1970). Study skills : for students of english as a second language. Estados Unidos: McGraw-Hill Interamericana.

MLA

Yorkey Richar C, . Study skills : for students of english as a second language. Estados Unidos: McGraw-Hill Interamericana. 1970.