Perhaps you should try some spelling variations:
cham tuc » nham thuc, pham thuc, tham thuc
su sach » so sach
hieu ve » hieu va, hieu van
han tai » hang tai, nhan tai, van tai
vu sach » vu bach, vu khach
mang xa » lang xa, mang may, dang xay
ve cham » va cham, ve chat, vu cham
va han » va phan, van han, va hanh
tuc va » thuc va, truc va, tuc xa
tai va » thai va, mai va, tri va
thiet » thieu

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) or (vu sach)) y ((mang xa) or (nang x)) hoi. hieu ve cham tuc va han tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) y ((mang xa) OR (nang x)) hoi. hieu ve cham tuc va han tai va thiet.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) y ((mang xa) or (nang x)) hoi. hieu ve cham tuc va han tai va thiet*.