Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
van hanh » van thanh, ban hanh, van anh
hanh hai » thanh hai, nhanh hai, hang hai
su triet » su viet, su tien, ve triet
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
su sai » su tai, su hai, su dai
sai ky » sac ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky tang xa hoi. hieu vien cac duc van hanh hai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky tang xa hoi. hieu vien cac duc van hanh hai ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: su sai ky tang xa hoi. hieu vien cac duc van hanh hai ((cua tre) or (su triet))*.