Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
hieu vien » hieu hien, hieu viec, thieu nien
doanh vai » doanh tai, doanh va, doanh van
nang xa » nang x, lang xa, nang ma
cach le » cach de, cach ben, cach lam
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
cac le » cac he, mac le, bac le

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