Perhaps you should try some spelling variations:
doanh vai » doanh tai, doanh va, doanh van
van doanh » toan doanh, van dong, van thanh
vien cac » vien bach, vien da, gian cac
vien dai » hien dai
vai cua » dai cua, hai cua, lai cua
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (sac ky)) nang xa hoi. hieu ((vien cac) OR (vien dai)) le van doanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang xa hoi. hieu ((vien cac) OR (vien dai)) le van doanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang xa hoi. hieu ((vien cac) OR (vien dai)) le van doanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang xa hoi. hieu ((vien cac) OR (vien dai)) le van doanh vai cua tre*.