Perhaps you should try some spelling variations:
thuoc tan » thuoc tai, thuoc ban, thuoc tren
sach thue » sach thu, sach thieu, sach tham
lam thuoc » nam thuoc, am thuc, cay thuoc
sach ty » sach y, sach tu, sach thu
tan anh » tuan anh, tran anh, toan anh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
anh vi » hanh vi, anh va, anh ve
vi cua » vai cua, di cua

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 ty) or (sach thue)) nang xa hoi. ((hieu ve) or (lieu va)) lam thuoc tan anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thue)) nang xa hoi. ((hieu ve) OR (lieu va)) lam thuoc tan anh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thue)) nang xa hoi. ((hieu ve) or (lieu va)) lam thuoc tan anh vi cua tre*.