Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thu hang » thi hang, thuc hanh, thu huong
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
ban hanh » ban hang
sach thu » sach thue, sach thieu, sach tham
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
cam duc » cao duc, pham duc, nam duoc
hang ca » hang va, nang cao, hang tai
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 thu hang ca hoi. hieu van ((cam duc) OR (cam xuc)) ban hanh vai ((cua tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu hang ca hoi. hieu van ((cam duc) OR (cam xuc)) ban hanh vai ((cua tre) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu hang ca hoi. hieu van ((cam duc) OR (cam xuc)) ban hanh vai ((cua tre) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: su sach thu hang ca hoi. hieu van ((cam duc) OR (cam xuc)) ban hanh vai ((cua tre) or (cua viet))*.