Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
sach tham » sach nha
ban hanh » ban hang
thuc ban » thuoc ban, thuc dan, thu ban
da thuc » dan thuc, dai thuc, dam thuc
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) or (sach tham)) nang ma hoi. ((hieu vien) or (hieu ve)) da thuc ban hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach tham)) nang ma hoi. ((hieu vien) OR (hieu ve)) da thuc ban hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach tham)) nang ma hoi. ((hieu vien) or (hieu ve)) da thuc ban hanh vi cua te*.