Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
duc manh » suc manh, duc anh, duc minh
manh anh » minh anh, anh anh, thanh anh
cua tre » cua te, cuu tre, dua tren
anh thi » anh tho, dinh thi, dang thi
dang ha » dong ha, dung ha, lang ha
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
sac ky » cac ky
ve cao » va cao, ve bao, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sai ky) or (sac ky)) dang ha noi. hieu ve cao duc manh anh thi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sai ky) OR (sac ky)) dang ha noi. hieu ve cao duc manh anh thi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sai ky) or (sac ky)) dang ha noi. hieu ve cao duc manh anh thi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: su ((sai ky) or (sac ky)) dang ha noi. hieu ve cao duc manh anh thi ((cua tre) OR (cua triet))*.