Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
nam thuc » nam thuoc, am thuc, nam thu
hoc sach » hoc sinh, hoc cac, hoc anh
hanh dai » hanh tai, hanh dao, vanh dai
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
dai cuu » dai cua, dai huu
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (hoc sach)) ky lang xa hoi. ((hieu van) or (lieu va)) nam thuc dan hanh dai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky lang xa hoi. ((hieu van) OR (lieu va)) nam thuc dan hanh dai cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky lang xa hoi. ((hieu van) or (lieu va)) nam thuc dan hanh dai cuu tre*.