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
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
cac toc » cac toi, cac nuoc, cac thoi
van anh » van thanh, tuan anh, van minh
ve su » va 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 toc ((van hanh) or (van anh)) ve su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. thieu nien cac toc ((van hanh) OR (van anh)) ve su triet.
• Adding a wildcard symbol may retrieve word variants: su sach ty nang xa hoi. thieu nien cac toc ((van hanh) or (van anh)) ve su triet*.