Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
sach duy » sach dung, sach duoc, sach dao
duy sang » duy van, duy can, duy anh
hanh lai » hanh lam, hanh tai, thanh lap
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, dua tren
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
cac xuc » cam xuc, cac nuoc, chat xuc
van cac » van hac, van cau, van bac
xuc va » duc va, tuc va, luc va
ma hoi » mai hoi, ma hoa, me hoi

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 duy sang ((ma hoi) or (xa hoi)). hieu van cac xuc va hanh lai ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach duy sang ((ma hoi) OR (xa hoi)). hieu van cac xuc va hanh lai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach duy sang ((ma hoi) or (xa hoi)). hieu van cac xuc va hanh lai ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach duy sang ((ma hoi) or (xa hoi)). hieu van cac xuc va hanh lai ((cua tre) OR (cua triet))*.