Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu vien » hieu viec, thieu nien, hieu tieng
ve triet » va trien, su triet
vat hanh » vat thanh, van hanh, va hanh
hoc vat » hoc va, hoc viet, thuc vat
cac hoc » cach hoc, cac hop, bac hoc
su sach » so sach
nang xa » nang x, lang xa, nang ma
vu sach » vu bach, vu khach
y nang » ky nang, ly nang, v nang
vi ve » va ve, gi ve, ve ve

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