Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
pham duy » pham duc
ve pham » vi pham, v pham, ve phan
tinh di » tinh doi, trinh di, tinh da
duy may » duy mai, dung may, duy thay
sach tu » sach thu, cach tu, sach uu
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach thu, xach tay
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 tu) or (sach ty)) nang xa hoi. hieu ve pham duy may tinh di ((cua triet) OR (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach ty)) nang xa hoi. hieu ve pham duy may tinh di ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tu) or (sach ty)) nang xa hoi. hieu ve pham duy may tinh di ((cua triet) OR (cua viet))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sach ty)) nang xa hoi. hieu ve pham duy may tinh di ((cua triet) OR (cua viet))*.