(1968). Rubber Krishi - Sidhanthavum Prayogavum. Kottayam: Rubber Research Institute of India.
1968. Rubber Krishi - Sidhanthavum Prayogavum. Kottayam: Rubber Research Institute of India.
Rubber Krishi - Sidhanthavum Prayogavum. Kottayam: Rubber Research Institute of India. 1968.
