Perhaps you should try some spelling variations:
dung tren » dung trong, dung trung
thanh lap » thanh san, phan lap, thanh hai
cau tren » cu tren, dau tren, ca tren
va thanh » gia thanh, ban thanh, va tinh
sach ty » sach y, sach tu, sach thu
te sach » toc sach
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
v pham » vi pham, d pham
hieu v » hieu va, hieu ve, hieu 2

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 ty ((nang ma) OR (sang ma)) hoi. hieu v pham duc va thanh lap ((dung tren) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang ma) OR (sang ma)) hoi. hieu v pham duc va thanh lap ((dung tren) or (cau tren))~".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((nang ma) OR (sang ma)) hoi. hieu v pham duc va thanh lap ((dung tren) or (cau tren))*.