Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sang mai » sang ma, sang tai, lang mai
van hanh » van thanh, ban hanh, van anh
nhan tuc » nhan thuc, nhan luc, nhanh thuc
va hanh » va thanh, va danh, ban hanh
hoi cua » hoi chuc
hai cua » thai cua, dai cua, lai cua
sach ly » sach y, sach lo, sach ty
va nhan » van nhan, ca nhan, va phan
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
ly sang » ly hang, ly san, ly vang

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 ly sang mai hoi. hieu va nhan tuc ((va hanh) or (van hanh)) ((hai cua) or (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ly sang mai hoi. hieu va nhan tuc ((va hanh) OR (van hanh)) ((hai cua) OR (hoi cua)) tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ly sang mai hoi. hieu va nhan tuc ((va hanh) or (van hanh)) ((hai cua) or (hoi cua)) tre*.