Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thuc van » thuc vat, thuc dan, thuc va
tu sach » thu sach, su sach, te sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
qua cam » qua cham, qua cac, qua ca
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
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 thu ((nang xa) or (lang xa)) hoi. hieu qua cam ((thuc van) or (duc van)) anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu ((nang xa) OR (lang xa)) hoi. hieu qua cam ((thuc van) OR (duc van)) anh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thu ((nang xa) or (lang xa)) hoi. hieu qua cam ((thuc van) or (duc van)) anh vi cua tre*.