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