Perhaps you should try some spelling variations:
thanh tay » thanh tai, thanh toan, thanh thuy
hieu van » hieu va, thien van, lieu va
sach ty » sach y, sach thu, xach tay
va hanh » van hanh, va thanh, va danh
cac tac » cac toc, cac bac, cac dac
van cac » van hac, van cau, van bac
su viet » so viet
sach tu » sach thu, cach tu, sach uu
tac va » tac da, tac xa, tuc va
xang o » lang o, tang o, dang o
o hoi » co hoi, o hoc, o hai
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((((sach ty) or (thanh tay))) or (sach tu)) xang o hoi. hieu van cac tac va hanh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((((sach ty) OR (thanh tay))) OR (sach tu)) xang o hoi. hieu van cac tac va hanh vi su viet.
• Adding a wildcard symbol may retrieve word variants: tu ((((sach ty) or (thanh tay))) or (sach tu)) xang o hoi. hieu van cac tac va hanh vi su viet*.