Perhaps you should try some spelling variations:
su sach » so sach, vu sach
tu hung » tu chung, tu nhung, tu vung
hung xa » chung xa, huong xa, hung ha
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (hoc cao)) tu hung xa hoi. hieu ve pham duc va hanh va ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (hoc cao)) tu hung xa hoi. hieu ve pham duc va hanh va ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (hoc cao)) tu hung xa hoi. hieu ve pham duc va hanh va ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (hoc cao)) tu hung xa hoi. hieu ve pham duc va hanh va ((cua tre) OR (cua te))*.