Perhaps you should try some spelling variations:
hieu vien » hieu viec, thieu nien, hieu tieng
hieu hien » bieu hien, dieu hien, chieu chien
ve triet » va trien, su triet
va triet » va thiet, va trien, cua triet
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
su sach » so sach, vu sach

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 dang xa hoi. ((hieu vien) or (hieu hien)) cac tuc van hanh vi ((va triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky dang xa hoi. ((hieu vien) OR (hieu hien)) cac tuc van hanh vi ((va triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky dang xa hoi. ((hieu vien) or (hieu hien)) cac tuc van hanh vi ((va triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ky dang xa hoi. ((hieu vien) or (hieu hien)) cac tuc van hanh vi ((va triet) OR (ve triet))*.