Perhaps you should try some spelling variations:
trinh hieu » trinh dieu, trinh thiet, trinh nhiet
viet cham » viet nam, viet ha, viet phan
qua canh » quat canh, qua danh, luat canh
ca nguoi » cua nguoi, cho nguoi, con nguoi
va nguoi » cua nguoi, dao nguoi, hoa nguoi
cham hoc » cham soc, chat hoc, cham hoi
hien han » hien hanh, hien huan, dien han

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: giao trinh hieu qua canh ((ca nguoi) or (va nguoi)) viet cham hoc hien han~.
• If you are trying to use Boolean operators, they must be ALL CAPS: giao trinh hieu qua canh ((ca nguoi) OR (va nguoi)) viet cham hoc hien han.
• Adding a wildcard symbol may retrieve word variants: giao trinh hieu qua canh ((ca nguoi) or (va nguoi)) viet cham hoc hien han*.