Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
mai khoi » mai khoa, tai khoa, cac khoi
cham tuc » nham thuc, pham thuc, tham thuc
mai hoi » dai hoi, lai hoi, mai doi
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
ky sang » ky nang, ky dang, ky tang
vai cau » va cau, van cau, lai chau
vai cac » va cac, tai cac, voi cac
ve cham » va cham, ve chat, vu cham
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky sang ((mai hoi) or (mai khoi)). hieu ve cham tuc va danh ((vai cau) or (vai cac)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky sang ((mai hoi) OR (mai khoi)). hieu ve cham tuc va danh ((vai cau) OR (vai cac)) tren.
• Adding a wildcard symbol may retrieve word variants: thu sach ky sang ((mai hoi) or (mai khoi)). hieu ve cham tuc va danh ((vai cau) or (vai cac)) tren*.