Perhaps you should try some spelling variations:
vien cac » vien dai, vien da, gian cac
vat hanh » vat thanh, van hanh, va hanh
ve triet » va trien, su triet
su sach » vu sach
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
hoc vat » hoc va, hoc viet, thuc vat
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 (so sach)) y nang xa hoi. hieu ((vien cac) or (vien bach)) hoc vat hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) y nang xa hoi. hieu ((vien cac) OR (vien bach)) hoc vat hanh vi ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) y nang xa hoi. hieu ((vien cac) or (vien bach)) hoc vat hanh vi ve triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) y nang xa hoi. hieu ((vien cac) or (vien bach)) hoc vat hanh vi ve triet*.