Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
qua cham » qua hai, qua cac, va cham
dung doi » huong doi, dung tai, dung co
vat dung » van dung, va dung, viet dung
cham tu » pham tu, cam tu, chai tu
sach ty » sach tu, sach thu, xach tay
tu vat » tu va, tu van, tu bat
nang o » nang co, nang ho, nang ro
o hoc » co hoc, mo hoc, so hoc

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 ty) or (sach y)) nang o hoc. hieu qua cham tu vat dung doi ((cua triet) OR (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) nang o hoc. hieu qua cham tu vat dung doi ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sach y)) nang o hoc. hieu qua cham tu vat dung doi ((cua triet) OR (su triet))".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach y)) nang o hoc. hieu qua cham tu vat dung doi ((cua triet) OR (su triet))*.