1. Abdel Latif, Abdulrazzak, Alaa Salih Ati, Shaima Sami Dawood and Osama Hussein Gower (2018). The Effect of Speed and Tillage Depths on Some Machinery Units Performance Indicators, Growth and Yield of Corn (Zea mays L.) Using Fifth Purposes Combine Equipment, Iraqi Journal of Agricultural Sciences, Volume (18), No.(1).
2. Aday, Shaker H. , H. El-edan and J C. Al-maliky (2010). Further development of a modified chisel plow and studying: (A) The draft force and power requirements and the ability of soil pulverization (MWD) (part1). Basrah J. Agric. Sci ,Vol.(23). No.(1).
3. Ahaneku, I. E. O. , A. Ouelade , and T. Faleye (2010). Comparative fild Evaluation of three model of atractor. Corresponding authors. E-mail:darha-neku@ yahoo.com.
4. AL-hashem, Hasan A. , Sirelkatim K. Abbouda and Mohamed O. Saeed (2000). The effect of Rear Wheel Track Width and Working depth on Performance of A2WD tractor. Res. Bult. No (93), Res. Cent. Coll. Of Agri., King Saud Univ ,(5-21).
5. AL-Obaidi, Yahya Younis Mohsin (2018). Evaluation of heavy chisel plow performance in different speeds in terms of some mechanical performance indicators, M.Sc. Thesis, Department of Agricultural Machinery and Equipment, College of Agriculture and Forestry, University of Mosul.