Perhaps you should try some spelling variations:
thieu nien » thien nhien
van hanh » van thanh, ban hanh, van ban
su triet » su viet, ve triet
nien cac » vien cac, dien cac, bien cac
sach ty » sach y, sach tu, sach thu
van anh » van thanh, tuan anh, van minh
su sach » so sach, vu sach
cac toc » cac toi, cac nuoc, cac thoi
ty nang » ky nang, ty xang, ty hang
su tien » su kien, su hien, tu tieng
x hoi » xa hoi, o hoi, x ho

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