Perhaps you should try some spelling variations:
diem cau » dieu can
canh tac » canh tay, canh giac, cong tac
van hanh » van thanh, ban hanh, van anh
luc van » luoc van, luu van, duc van
te sach » toc sach
sach ky » sac ky, sach y, sach ty
tac hoi » tao hoi, tay hoi, tac hai
ky canh » ky anh, ky cach, ky danh
va cam » va cham, va cac, va cai
di cau » da cau
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky canh tac hoi. lieu ((va cam) or (va cao)) luc van hanh ((di cau) OR (diem cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky canh tac hoi. lieu ((va cam) OR (va cao)) luc van hanh ((di cau) OR (diem cau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky canh tac hoi. lieu ((va cam) or (va cao)) luc van hanh ((di cau) OR (diem cau)) tren".
• Adding a wildcard symbol may retrieve word variants: te sach ky canh tac hoi. lieu ((va cam) or (va cao)) luc van hanh ((di cau) OR (diem cau)) tren*.