Perhaps you should try some spelling variations:
trinh chao » trinh chat, trinh han, trinh co
trinh cao » trinh co, tinh cao, trinh cho
chao luan » khao luan, phap luan, khau luan
loai viet » ngoai viet, hoa viet, luat viet
cong loai » cong lai, cong hoa, cong hai
trinh cau » trinh chat, trinh tu, trinh han
cong loi » cong li, cong lon, cong goi
cau luan » cu luan, dau luan, lau luan
loi viet » hoi viet, oi viet, doi viet
cac cong » cua cong
cac cac » cac cach, ca cac, cac bac
luan va » luan van, luat va
lan van » luan van, lang van, tan van
lan va » lanh va, lang va, ban va
co loi » co hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((( cong trinh cao ((lan va) OR (lan van)) cac cac cong loi viet nam ) or ( cong trinh cau luan va cac cac cong loai viet nam ))) or ( cong trinh chao luan va cac cac co loi viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh cao ((lan va) OR (lan van)) cac cac cong loi viet nam ) OR ( cong trinh cau luan va cac cac cong loai viet nam ))) OR ( cong trinh chao luan va cac cac co loi viet nam )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( cong trinh cao ((lan va) OR (lan van)) cac cac cong loi viet nam ) or ( cong trinh cau luan va cac cac cong loai viet nam ))) or ( cong trinh chao luan va cac cac co loi viet nam ))".
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh cao ((lan va) OR (lan van)) cac cac cong loi viet nam ) or ( cong trinh cau luan va cac cac cong loai viet nam ))) or ( cong trinh chao luan va cac cac co loi viet nam ))*.