Perhaps you should try some spelling variations:
trinh thien » trinh thiet, trinh nghien, trinh tin
trinh tien » trinh tieng, trinh tin, trinh dien
luan mang » luan nang, luan tang, luan van
viet khoa » vien khoa, viec khoa, viet khoang
vien than » vien thanh, dien than, vien nhan
mang cua » manh cua, dung cua, ban cua
khoa hoc » hoa hoc
dien han » dien phan, dien than, dien dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: giao ((trinh thien) OR (trinh tien)) luan mang cua nguoi viet khoa hoc ((dien han) or (vien than))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: giao ((trinh thien) OR (trinh tien)) luan mang cua nguoi viet khoa hoc ((dien han) OR (vien than)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "giao ((trinh thien) OR (trinh tien)) luan mang cua nguoi viet khoa hoc ((dien han) or (vien than))".
• Adding a wildcard symbol may retrieve word variants: giao ((trinh thien) OR (trinh tien)) luan mang cua nguoi viet khoa hoc ((dien han) or (vien than))*.