Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh vi, hanh tai, hanh van
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cua tre » cua te, cuu tre, dua tren
hanh va » hang va, hanh vi
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
sach ky » sac ky, sach y, sach ty
soc va » hoc va, loc va, doc va
ma hoi » mai hoi, xa hoi, ma hoa

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 ma hoi. hieu van cham soc va ((hanh vai) or (hanh va)) ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. hieu van cham soc va ((hanh vai) OR (hanh va)) ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. hieu van cham soc va ((hanh vai) or (hanh va)) ((cua tre) or (cua triet))*.