APA

Roling N., . (1990). Extension science. Information systems in agricultural development. Cambridge: Cambridge University Press.

Chicago

Roling Niels, . 1990. Extension science. Information systems in agricultural development. Cambridge: Cambridge University Press.

Harvard

Roling N., . (1990). Extension science. Information systems in agricultural development. Cambridge: Cambridge University Press.

MLA

Roling Niels, . Extension science. Information systems in agricultural development. Cambridge: Cambridge University Press. 1990.