APA

Gierbolini R. E., United States, . (1975). Soil survey of Mayaguez area of Western Puerto Rico: area de Mayaguez. et al. Washington: U.S. Govt. Print. Off.

Chicago

Gierbolini Robert E, United States, . 1975. Soil survey of Mayaguez area of Western Puerto Rico: area de Mayaguez. et al. Washington: U.S. Govt. Print. Off.

Harvard

Gierbolini R. E., United States, . (1975). Soil survey of Mayaguez area of Western Puerto Rico: area de Mayaguez. et al. Washington: U.S. Govt. Print. Off.

MLA

Gierbolini Robert E, United States, . Soil survey of Mayaguez area of Western Puerto Rico: area de Mayaguez. et al. Washington: U.S. Govt. Print. Off. 1975.