Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hien cac » thien cac, vien cac, hieu cac
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
mai hoi » mai khoi, lai hoi, mai doi
dai hoi » dai hoc, dai hai, dai moi
cac xuc » cam xuc, cac nuoc, chat xuc
va hanh » van hanh, va thanh, va danh
xuc va » duc va, tuc va, luc va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty nang ((mai hoi) or (dai hoi)). hieu hien cac xuc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((mai hoi) OR (dai hoi)). hieu hien cac xuc va hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((mai hoi) or (dai hoi)). hieu hien cac xuc va hanh vi cua viet*.