Perhaps you should try some spelling variations:
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
bao bo » bac bo, ban bo, bao bi
nao bo » nam bo
va anh » van anh, va danh, va hanh
anh va » hanh va
va cua » va chua, via cua, ca 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 ky ((nang ma) or (sang ma)) hoi. hieu va ((bao bo) or (nao bo)) va anh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang ma) OR (sang ma)) hoi. hieu va ((bao bo) OR (nao bo)) va anh va cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang ma) or (sang ma)) hoi. hieu va ((bao bo) or (nao bo)) va anh va cua tre*.