Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
van triet » va triet, van thiet, van trieu
vien cac » vien bach, vien dai, vien da
su sach » so sach, vu sach
ly nang » ky nang, ly vang, ly quang
ly hang » ly quang
thu va » thuc va, thue va, tu va

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