Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cao truc » cau truc, vao truc, cao thuoc
hanh tai » thanh tai, hang tai, han tai
hanh vai » hanh vi, hanh va, hanh van
truc va » thuc va, thuc vat, trung va
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
tu nang » tru nang, tu nong, tu nano
va cao » va cac, va co, va dao
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((tu nang) or (truc nano)) x hoi. hieu va cao truc va ((hanh vai) or (hanh tai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((tu nang) OR (truc nano)) x hoi. hieu va cao truc va ((hanh vai) OR (hanh tai)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((tu nang) or (truc nano)) x hoi. hieu va cao truc va ((hanh vai) or (hanh tai)) cuu tre*.