Perhaps you should try some spelling variations:
thong trong » thuong trong, thong thong, thong thuong
theo chieu » theo tieu, ho chieu, theo chu
chieu xanh » chieu sach, chieu sang, chieu tinh
trong mach » trong cac, trong minh, trong anh
mach toan » manh toan, hach toan, mach tuan
thang va » hang va, thong va, thanh va
trang va » tran van, hang va
toan cau » toan cao, toan ban, toan tap
tang va » tang van, tang vat, hang va

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu xanh - anh ((tang va) or (((thang va) OR (trang va)))) thong trong mach toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu xanh - anh ((tang va) OR (((thang va) OR (trang va)))) thong trong mach toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu xanh - anh ((tang va) or (((thang va) OR (trang va)))) thong trong mach toan cau".
• Adding a wildcard symbol may retrieve word variants: theo chieu xanh - anh ((tang va) or (((thang va) OR (trang va)))) thong trong mach toan cau*.