Perhaps you should try some spelling variations:
su sach » so sach, vu sach
hoc cac » hoc cao
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
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren

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