Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
vien cac » vien bach, vien dai, vien da
sach ty » sach y, sach tu, sach thu
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
ve cac » va cac
va dau » va dao
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty lang xa hoi. hieu ((ve cac) OR (vien cac)) xuc ((van doanh) or (va dau)) vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty lang xa hoi. hieu ((ve cac) OR (vien cac)) xuc ((van doanh) OR (va dau)) vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty lang xa hoi. hieu ((ve cac) OR (vien cac)) xuc ((van doanh) or (va dau)) vi cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ty lang xa hoi. hieu ((ve cac) OR (vien cac)) xuc ((van doanh) or (va dau)) vi cua te*.