Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cua viet » ca viet, hoa viet, cua vat
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
y tang » ky tang, 6 tang, 7 tang
ma hoi » mai hoi, xa hoi, ma hoa
ve cau » ke cau, va cau, ve cac
luc va » duc va, tuc va
loc va » hoc va
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: hoc sach y tang ma hoi. hieu ve cau ((luc va) or (loc va)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y tang ma hoi. hieu ve cau ((luc va) OR (loc va)) hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: hoc sach y tang ma hoi. hieu ve cau ((luc va) or (loc va)) hanh vi cua viet*.