Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cac duc » cao duc, cac dac, cac nuoc
sach ty » sach y, sach tu, sach thu
te sach » toc sach
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, me hoi
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty nang ((ma hoi) or (ma hoa)). hieu qua ((cac duc) or (cac du)) va hanh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang ((ma hoi) OR (ma hoa)). hieu qua ((cac duc) OR (cac du)) va hanh di cua viet.
• Adding a wildcard symbol may retrieve word variants: te sach ty nang ((ma hoi) or (ma hoa)). hieu qua ((cac duc) or (cac du)) va hanh di cua viet*.