Perhaps you should try some spelling variations:
sach tham » sach nha
pham day » phap day, pham duy, pham xay
van chat » cao chat
va doanh » van doanh, vay doanh, va danh
van cau » van dau, van hau, toan cau
tu sach » thu sach, su sach, te sach
ve pham » vi pham, v pham, ve phan
mang xa » lang xa, mang may, dang xay
hieu ve » hieu va, hieu van

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 tham ((mang xa) or (nang x)) hoi. hieu ve pham day va doanh ((van cau) OR (van chat)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tham ((mang xa) OR (nang x)) hoi. hieu ve pham day va doanh ((van cau) OR (van chat)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tham ((mang xa) or (nang x)) hoi. hieu ve pham day va doanh ((van cau) OR (van chat)) tren".
• Adding a wildcard symbol may retrieve word variants: tu sach tham ((mang xa) or (nang x)) hoi. hieu ve pham day va doanh ((van cau) OR (van chat)) tren*.