Broadbent, L., Burt, P. E. and Nix, J. S. 1957. The cost of using insecticides to maintain the health of potato seed in England and Wales. NAAS Quarterly Review. 38 (Winter), pp. 144-153.
Boyd, D. A., Church, B. M., Hills, M. G. and Heafield, T. G. 1966. Types of fertilizers used on farm crops in England and Wales. NAAS Quarterly Review.