Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
pham duy » pham duc
cua viet » ca viet, hoa viet, cua vat
sach tu » cach tu, sach ty, sach uu
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duy may » duy mai, dung may, duy thay
tinh di » tinh doi, trinh di, tinh da
di cua » dai cua, doi cua, de cua

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 tu) or (sach thu)) nang xa hoi. hieu ve pham duy may tinh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach thu)) nang xa hoi. hieu ve pham duy may tinh di cua viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sach thu)) nang xa hoi. hieu ve pham duy may tinh di cua viet*.