Perhaps you should try some spelling variations:
trinh tuan » trinh quan, trinh toan, trinh xuan
trinh luan » trinh luat, trinh quan, trinh han
phuong lan » phuong la, thuong lan, phuong linh
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
than cau » toan cau, phan cau, than cap

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 xanh - hanh ((trinh tuan) OR (trinh luan)) duong ((phuong lan) or (thuong mai)) than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh ((trinh tuan) OR (trinh luan)) duong ((phuong lan) OR (thuong mai)) than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - hanh ((trinh tuan) OR (trinh luan)) duong ((phuong lan) or (thuong mai)) than cau".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh ((trinh tuan) OR (trinh luan)) duong ((phuong lan) or (thuong mai)) than cau*.