Perhaps you should try some spelling variations:
chet duoc » che duoc, cho duoc, che quoc
hang dai » hoang dai, hang tai, hang dau
duoc van » duoc va, duc van, duoc ban
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
ly hang » ly quang
hieu va » lieu va, hieu qua
va chet » va chiet, va che, va chat
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua

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 ly hang dai hoc. hieu va chet duoc van hanh ((vai cua) or (hai cua)) tuc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly hang dai hoc. hieu va chet duoc van hanh ((vai cua) OR (hai cua)) tuc.
• Adding a wildcard symbol may retrieve word variants: su sach ly hang dai hoc. hieu va chet duoc van hanh ((vai cua) or (hai cua)) tuc*.