How to get old papers?
Moody, W. T. (1966). Nonlinear differential equation of drain spacing. Journal of the Irrigation and Drainage Division, 92(2), 1-10.
Sakkas, J. G., & Antonopoulos, V. Z. (1981). Simple equations for Hooghoudt equivalent depth. Journal of the Irrigation and Drainage Division, 107(4), 411-414.
Sakkas, J. G. (1975). Generalized nomographic solution of Hooghoudt equations. Journal of the Irrigation and Drainage Division, 101(1), 21-39.
Mine can be the general answer but it connected to library and Information Science.
Finding the old documents and retrospective data events have greater historical value than any other expectations. The quite comparision can be done only with old paperswith new one.
Mostly, the libraries have archives might have stored and kept for future use.
Researcher can find out the Repositories of Irrigation and Water Management Institute (IWMI) in every country.
Old papers could bring the old citations which have signify impact in the field of research and academic publications.
