Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
van hanh » van thanh, ban hanh, van anh
cap nuoc » dat nuoc
cua viet » ca viet, hoa viet, cua vat
nang cai » nang cao, nang tai, nang cap
cai hoi » cau hoi, dai hoi, cai hoa
sach tu » sach thu, cach tu, sach ty
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: tu ((sach y) or (sach tu)) nang cai hoi. hieu hien ((cap nuoc) or (cam xuc)) van hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach y) OR (sach tu)) nang cai hoi. hieu hien ((cap nuoc) OR (cam xuc)) van hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach y) or (sach tu)) nang cai hoi. hieu hien ((cap nuoc) or (cam xuc)) van hanh vi cua viet*.