APA
Cropley A. J., . (1977). Lifelong education. Pergamon, Oxford: .
Chicago
Cropley A J, . 1977. Lifelong education. Pergamon, Oxford: .
Harvard
Cropley A. J., . (1977). Lifelong education. Pergamon, Oxford: .
MLA
Cropley A J, . Lifelong education. Pergamon, Oxford: . 1977.