Perhaps you should try some spelling variations:
thong trong » thuong trong, thong thong, thong thuong
thieu xanh » chieu xanh, thien anh, thien danh
trong phap » trong phat, trong thap, chong phap
hieu manh » chieu xanh, hieu nganh, dieu hanh
trong van » trong cac
van toan » van tuan, van tan, van thanh
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 ((thieu xanh) OR (hieu manh)) - thanh ((trong phap) or (trong nha)) thong trong van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (hieu manh)) - thanh ((trong phap) OR (trong nha)) thong trong van toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (hieu manh)) - thanh ((trong phap) or (trong nha)) thong trong van toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (hieu manh)) - thanh ((trong phap) or (trong nha)) thong trong van toan cau*.