APA

Purcell D. L., Anderson J. R., . (1997). Agricultural extension and research. Washington, D.C: World Bank.

Chicago

Purcell Dennis L, Anderson Jock R, . 1997. Agricultural extension and research. Washington, D.C: World Bank.

Harvard

Purcell D. L., Anderson J. R., . (1997). Agricultural extension and research. Washington, D.C: World Bank.

MLA

Purcell Dennis L, Anderson Jock R, . Agricultural extension and research. Washington, D.C: World Bank. 1997.