Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
cac thu » cach thuc, cac thoi
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
va danh » va dinh, va dan, va hanh
van cac » van hac, van cau, van bac
nang ma » tang ma, sang ma, nang cao
thu va » thuc va, thue va, tu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y ((nang x) or (nang ma)) hoi. hieu van cac thu va danh ((vai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((nang x) OR (nang ma)) hoi. hieu van cac thu va danh ((vai cua) OR (hai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang x) or (nang ma)) hoi. hieu van cac thu va danh ((vai cua) or (hai cua)) tre*.