Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh vi, hanh va, hanh tai
cam luc » cam xuc, cau luc
cua tre » cua te, cuu tre, dua tren
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
lang ha » long ha
luc va » duc va, tuc va, loc va
ve cam » ve cham, ve cac, va cam

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 ky ((nang x) or (lang ha)) hoi. hieu ve cam luc va hanh vai ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang x) OR (lang ha)) hoi. hieu ve cam luc va hanh vai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang x) or (lang ha)) hoi. hieu ve cam luc va hanh vai ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang x) or (lang ha)) hoi. hieu ve cam luc va hanh vai ((cua tre) OR (cua triet))*.