Perhaps you should try some spelling variations:
kham duc » pham duc, kham cuoc, pham duy
va doanh » van doanh, vay doanh, va danh
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu vu » hieu va, hieu ve, hieu su
vu kham » vu khanh
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo

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 xang xa hoi. hieu vu kham duc va doanh tai ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty xang xa hoi. hieu vu kham duc va doanh tai ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: so sach ty xang xa hoi. hieu vu kham duc va doanh tai ((cua tre) or (cuu tre))*.