Perhaps you should try some spelling variations:
dang xay » dang van, van xay
cau tren » cu tren, dau tren, ca tren
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
ty dang » ty xang, ky dang, ty hang
xay hoi » xa hoi, tay hoi, cay phoi
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
hieu v » hieu va, hieu ve, hieu 2
v pham » vi pham, d pham

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty dang xay hoi. hieu v pham duc va hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty dang xay hoi. hieu v pham duc va hanh vi ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: so sach ty dang xay hoi. hieu v pham duc va hanh vi ((cua tre) or (cau tren))*.