Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
sach thu » sach thieu, sach tham, cach thuc
van hanh » van thanh, ban hanh, van anh
hanh va » hang va, hanh vi
tuc van » thuc van, truc van, tuc va
ve cham » va cham, ve chat, vu cham
tang ma » mang may, tang van
ma hoi » mai hoi, xa hoi, ma hoa
va hoa » van hoa, va hoc, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach thu) or (sach thue)) tang ma hoi. hieu ((ve cham) or (va cac)) tuc van hanh va hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach thu) OR (sach thue)) tang ma hoi. hieu ((ve cham) OR (va cac)) tuc van hanh va hoa viet.
• Adding a wildcard symbol may retrieve word variants: su ((sach thu) or (sach thue)) tang ma hoi. hieu ((ve cham) or (va cac)) tuc van hanh va hoa viet*.