Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
van hanh » van thanh, ban hanh, van ban
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cac hoc » cach hoc, cac hop, bac hoc
sach ty » sach y, sach tu, sach thu
van anh » van thanh, tuan anh, van minh
su sach » so sach, vu sach
vi su » va su, ve su, oi su
ki su » ky su

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