Perhaps you should try some spelling variations:
thien van » thi van
thanh dai » thanh hai, thanh tai, thanh dat
cua triet » cua viet, su triet, va triet
hieu van » hieu va, lieu va, hieu ve
va thanh » gia thanh, ban thanh, va tinh
te sach » toc sach
tang ma » mang may, tang van
cua tre » cua te, cuu tre, dua tren
y tang » ky tang, 6 tang, 7 tang
ma hoi » mai hoi, xa hoi, ma hoa
du va » dau va, tu va, su va

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: te sach y tang ma hoi. ((hieu van) OR (thien van)) cac du va thanh dai ((cua tre) OR (cua triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y tang ma hoi. ((hieu van) OR (thien van)) cac du va thanh dai ((cua tre) or (cua triet))~".
• Adding a wildcard symbol may retrieve word variants: te sach y tang ma hoi. ((hieu van) OR (thien van)) cac du va thanh dai ((cua tre) or (cua triet))*.