Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cau loc » hau loc, cau hoc, cau luc
va hanh » van hanh, va thanh, va danh
cu tren » tu tren, dua tren
loc va » hoc va, luc va
vi cu » vi su, vi xu, vi du

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang ma) OR (lang xa)) hoi. ((hieu van) OR (hieu va)) cau loc va hanh vi cu tren~.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ma) or (lang xa)) hoi. ((hieu van) or (hieu va)) cau loc va hanh vi cu tren*.