Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
cam truc » cau truc, nam truc, lam truoc
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
van cam » van nam, van lam, van cau
mai hoi » mai khoi, dai hoi, lai hoi
ma hoi » xa hoi, ma hoa, me hoi
sai ky » sac ky
vi cua » vai cua, di cua

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 ky) or (sai ky)) nang ((ma hoi) OR (mai hoi)). hieu van cam truc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sai ky)) nang ((ma hoi) OR (mai hoi)). hieu van cam truc va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sai ky)) nang ((ma hoi) OR (mai hoi)). hieu van cam truc va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sai ky)) nang ((ma hoi) OR (mai hoi)). hieu van cam truc va hanh vi cua viet*.