Perhaps you should try some spelling variations:
hanh manh » hanh mang, hoang manh, thanh minh
lanh manh » lanh tranh, lan anh, van manh
cua thong » cua thuong, cua khong, cua tong
thong tac » thong cac, tuong tac, thong tai
ho chieu » theo chieu, hoc thieu, doi chieu
tac toan » tap toan, tam toan, hach toan
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: ((hoc hien) or (ho chieu)) xanh - ((hanh manh) OR (lanh manh)) cua thong thong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc hien) OR (ho chieu)) xanh - ((hanh manh) OR (lanh manh)) cua thong thong tac toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc hien) or (ho chieu)) xanh - ((hanh manh) OR (lanh manh)) cua thong thong tac toan cau".
• Adding a wildcard symbol may retrieve word variants: ((hoc hien) or (ho chieu)) xanh - ((hanh manh) OR (lanh manh)) cua thong thong tac toan cau*.