Perhaps you should try some spelling variations:
trinh hieu » trinh dieu, trinh thiet, trinh nhiet
viet theo » viet tien, viet thuc, viet tiep
qua canh » quat canh, qua danh, luat canh
va nguoi » ca nguoi, cua nguoi, dao nguoi
viet cho » viec cho, viet co, viet cham
hien han » hien hanh, hien huan, dien han
canh va » canh van, hanh va, anh va

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 va nguoi ((viet cho) OR (viet theo)) hoc hien han~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "giao trinh hieu qua canh va nguoi ((viet cho) OR (viet theo)) hoc hien han".
• Adding a wildcard symbol may retrieve word variants: giao trinh hieu qua canh va nguoi ((viet cho) OR (viet theo)) hoc hien han*.