Perhaps you should try some spelling variations:
van triet » va triet, van thiet, van trieu
hieu vien » hieu hien, hieu viec, thieu nien
hoc sach » hoc sinh, hoc cac, hoc anh
ty nang » ty xang, ty hang, ly nang
cac dai » cac dan, cac bai, can dai
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
cac dac » cac dan, cac bac, cac tac
ve van » le van
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ((ty nang) OR (ky nang)) o hoi. hieu vien ((cac dac) or (cac dai)) va hanh ve van triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((ty nang) OR (ky nang)) o hoi. hieu vien ((cac dac) OR (cac dai)) va hanh ve van triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((ty nang) OR (ky nang)) o hoi. hieu vien ((cac dac) or (cac dai)) va hanh ve van triet".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((ty nang) OR (ky nang)) o hoi. hieu vien ((cac dac) or (cac dai)) va hanh ve van triet*.