Cita APA

Roberts, R. C. n. 1., & Roberts, R. C. n. 1. Soil map Puerto Rico: West-central sheet.

Citación estilo Chicago

Roberts, Ray Carlton n. 1901, y Ray Carlton n. 1901 Roberts. Soil Map Puerto Rico: West-central Sheet.

Cita MLA

Roberts, Ray Carlton n. 1901, y Ray Carlton n. 1901 Roberts. Soil Map Puerto Rico: West-central Sheet.