APA
Yogaratnam N, Perera M A, . (1981). Urea as a nitrogen fertilizer for rubber plantations in Sri Lanka. II. Agronomic investigations. : Journal of the Rubber Research Institute of Sri Lanka.
Chicago
Yogaratnam N, Perera M A, . 1981. Urea as a nitrogen fertilizer for rubber plantations in Sri Lanka. II. Agronomic investigations. : Journal of the Rubber Research Institute of Sri Lanka.
Harvard
Yogaratnam N, Perera M A, . (1981). Urea as a nitrogen fertilizer for rubber plantations in Sri Lanka. II. Agronomic investigations. : Journal of the Rubber Research Institute of Sri Lanka.
MLA
Yogaratnam N, Perera M A, . Urea as a nitrogen fertilizer for rubber plantations in Sri Lanka. II. Agronomic investigations. : Journal of the Rubber Research Institute of Sri Lanka. 1981.