PALANIAPPAN, K. S. S. P. “Turmeric - Maize and Onion Intercropping Systems. IV. PAR Interception”. Journal of Spices and Aromatic Crops, vol. 5, no. 2, Dec. 1996, pp. 139-42, https://updatepublishing.com/journal/index.php/josac/article/view/4382.