Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh vi, hanh va, hanh tai
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, dua tren
su sach » so sach, vu sach
cam duc » cam xuc, cao duc, pham duc
ly hang » ly quang
van cam » van nam, van lam, van cau
y hang » ty hang, yu hang, _ hang

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 ((y hang) OR (ly hang)) xa hoi. hieu van cam duc ban hanh vai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y hang) OR (ly hang)) xa hoi. hieu van cam duc ban hanh vai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y hang) OR (ly hang)) xa hoi. hieu van cam duc ban hanh vai ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ((y hang) OR (ly hang)) xa hoi. hieu van cam duc ban hanh vai ((cua tre) or (cua triet))*.