Perhaps you should try some spelling variations:
bieu mien » bien mien, bieu hien, bieu dien
mien bac » vien bach, dien ban, gian bac
van dinh » van minh, van dich, va dinh
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
vai cua » hai cua, lai cua, bai cua
bac so » bac son, bac si, bac bo
so van » su van, vo van

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. bieu mien bac so van dinh ((vai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. bieu mien bac so van dinh ((vai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty nang xa hoi. bieu mien bac so van dinh ((vai cua) or (dai cua)) tre*.