Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu vien » hieu hien, hieu viec, thieu nien
ban hanh » ban hang
cac thoi » cac toi, cac hop, cac tro
nang xa » nang x, lang xa, nang ma
sach ky » sac ky, sach y, sach kem
cac toc » cac toi, cac nuoc
sach ty » sach y, sach tu, sach thu
hanh di » hanh vi, hanh de, hang di
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: so ((sach ky) OR (sach ty)) nang xa hoi. hieu vien ((cac toc) or (cac thoi)) ban hanh di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ky) OR (sach ty)) nang xa hoi. hieu vien ((cac toc) OR (cac thoi)) ban hanh di cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ky) OR (sach ty)) nang xa hoi. hieu vien ((cac toc) or (cac thoi)) ban hanh di cua triet".
• Adding a wildcard symbol may retrieve word variants: so ((sach ky) OR (sach ty)) nang xa hoi. hieu vien ((cac toc) or (cac thoi)) ban hanh di cua triet*.