Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, lieu vien
khoa hoc » hoa hoc
vien da » vien dai, hien dai
luc van » luoc van, luu van, duc van
xuc van » duc van, vuc van, xuc ban
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
cho hoc » co hoc
tu nano » truc nano
cua cay » cua cac
anh va » hanh va
va cua » va chua, via cua, ca 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 tu nano ((cho hoc) or (khoa hoc)). hieu vien da ((xuc van) OR (luc van)) anh va cua cay~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nano ((cho hoc) OR (khoa hoc)). hieu vien da ((xuc van) OR (luc van)) anh va cua cay*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu nano ((cho hoc) or (khoa hoc)). hieu vien da ((xuc van) OR (luc van)) anh va cua cay*".