Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
hanh van » thanh van, khanh van, hanh va
cau tren » cu tren, dau tren, ca tren
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
van lam » van nam
van cau » van dau, van hau, van chat
lam co » nam co
co van » cao van, vo van, so van

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: so sach ty ((dong co) OR (van xay)) hoi. hieu van lam co van hanh van cau tren~.
• Adding a wildcard symbol may retrieve word variants: so sach ty ((dong co) or (van xay)) hoi. hieu van lam co van hanh van cau tren*.