Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
pham tai » pham thi, pham van
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
sach ky » sac ky, sach y, sach kem
va tinh » may tinh
tinh vi » trinh vi, tinh voi, tinh va
tai va » thai va, mai va, tri va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) OR (sach ty)) nang xa hoi. hieu van pham tai va tinh vi ((cua triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang xa hoi. hieu van pham tai va tinh vi ((cua triet) OR (va triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach ty)) nang xa hoi. hieu van pham tai va tinh vi ((cua triet) or (va triet))*".