Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh vi, hanh va, hanh tai
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
cua tre » cua te, cuu tre, dua tren
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
cam duc » cam xuc, cao duc, nam duoc
hang ca » hang va, nang cao, hang tai
ty hang » ly hang, ty xang, thi hang
ca hoi » cau hoi, cua hoi, xa hoi

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