Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
va trien » va truyen, va thiet, va tuyen
va triet » va thiet, ve triet, cua triet
van hanh » van thanh, ban hanh, van anh
cac dai » cac dan, cac bai, can dai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cac tac » cac toc, cac bac, cac dac
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang

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