Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
trinh vi » trinh va, trinh ve, trinh viet
va trinh » van trinh, va tinh, lap trinh
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
cac xuc » cam xuc, cac nuoc, chat xuc
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu
xuc va » duc va, tuc va, luc va

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 (thu sach)) ky tang xa hoi. ((hieu ve) OR (hieu van)) cac xuc va trinh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu sach)) ky tang xa hoi. ((hieu ve) OR (hieu van)) cac xuc va trinh vi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thu sach)) ky tang xa hoi. ((hieu ve) OR (hieu van)) cac xuc va trinh vi cua tu".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) ky tang xa hoi. ((hieu ve) OR (hieu van)) cac xuc va trinh vi cua tu*.