Perhaps you should try some spelling variations:
manh tuong » manh tung, manh cuong, minh tuong
hieu sang » chieu sang, hieu lang, hieu quang
tuong qua » tuong quan, duong qua, thong qua
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sang - manh tuong qua song ((cong dan) or (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - manh tuong qua song ((cong dan) OR (cong san)) toan cau.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - manh tuong qua song ((cong dan) or (cong san)) toan cau*.