Perhaps you should try some spelling variations:
tinh ven » trinh ven, tinh yen, sinh vien
su sach » so sach, vu sach
cac duc » cac du, cao duc, cac dac
cua tre » cua te, cua triet, dua tren
va tinh » may tinh
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cuu tre » cau tren, cau treo

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