Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
van anh » van thanh, tuan anh, van minh
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
cua cay » cua cac
hieu ve » hieu va
cao hoc » co hoc, cho hoc, chat hoc
tu nang » tru nang, tu nong, tu nano
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: ((te sach) OR (toc sach)) tu nang cao hoc. ((hieu ve) or (hieu van)) cac luc van anh vi cua cay~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu nang cao hoc. ((hieu ve) OR (hieu van)) cac luc van anh vi cua cay*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) tu nang cao hoc. ((hieu ve) or (hieu van)) cac luc van anh vi cua cay*".