APA
John R S, . (1967). Pottassium status of some soils in the rubber growing areas of Ceylon. : Rubber Research Institute of Ceylon Quarterly Journal.
Chicago
John R S, . 1967. Pottassium status of some soils in the rubber growing areas of Ceylon. : Rubber Research Institute of Ceylon Quarterly Journal.
Harvard
John R S, . (1967). Pottassium status of some soils in the rubber growing areas of Ceylon. : Rubber Research Institute of Ceylon Quarterly Journal.
MLA
John R S, . Pottassium status of some soils in the rubber growing areas of Ceylon. : Rubber Research Institute of Ceylon Quarterly Journal. 1967.