Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
va doanh » van doanh, vay doanh, va danh
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
cuc tre » duc tre, cua tre, cuu tre
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky ((sang ma) or (nang ma)) hoi. ((hieu ve) OR (hieu va)) cac xuc va doanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky ((sang ma) OR (nang ma)) hoi. ((hieu ve) OR (hieu va)) cac xuc va doanh tai cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky ((sang ma) or (nang ma)) hoi. ((hieu ve) OR (hieu va)) cac xuc va doanh tai cuc tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky ((sang ma) or (nang ma)) hoi. ((hieu ve) OR (hieu va)) cac xuc va doanh tai cuc tre*.