Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
thanh dat » thanh san, thanh hai, thanh van
sach thu » sach thue, sach thieu, sach tham
va triet » va thiet, va trien, ve triet
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
ve pham » vi pham, ve phan, ve phat
v pham » vi pham, d pham

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 ty) or (sach thu)) nang xa hoi. hieu ((ve pham) OR (v pham)) duc tan thanh dat va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang xa hoi. hieu ((ve pham) OR (v pham)) duc tan thanh dat va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach thu)) nang xa hoi. hieu ((ve pham) OR (v pham)) duc tan thanh dat va triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) nang xa hoi. hieu ((ve pham) OR (v pham)) duc tan thanh dat va triet*.