Chertkiattipol, S., Niyamapa, T. and Salokhe, V. 2009. Study on the Specic Tilling Energy of Three Types of the Rotary Blades  . Thai Agricultural Research Journal. 27, 3 (Dec. 2009), 316. DOI:https://doi.org/10.14456/thaidoa-agres.2009.22.