Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
hang vi » hanh vi, hang di, khang voi
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
tuc va » thuc va, truc va, tuc xa

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 y nang ma hoa. hieu ve cac tuc va ((hang vi) or (hang va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoa. hieu ve cac tuc va ((hang vi) OR (hang va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ma hoa. hieu ve cac tuc va ((hang vi) or (hang va)) cua tre*.