Perhaps you should try some spelling variations:
trinh tuan » trinh quan, trinh luan, trinh xuan
trinh toan » tinh toan, thanh toan, trinh han
trong dan » trong dang, trong san, trong tan
chi sang » chi lang, chieu sang, chi chang
toan cao » toan tap
toan ban » van ban
doi chi » doi khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chi sang - hanh ((trinh tuan) OR (trinh toan)) dung trong dan ((toan cao) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chi sang - hanh ((trinh tuan) OR (trinh toan)) dung trong dan ((toan cao) OR (toan ban))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chi sang - hanh ((trinh tuan) OR (trinh toan)) dung trong dan ((toan cao) or (toan ban))*".