Perhaps you should try some spelling variations:
trinh sau » trinh san, trinh cau, trinh su
cau giay » cuu giai, cac giai
sau luan » su luan, dau luan, sau lan
soi viet » hoi viet, oi viet, doi viet
cao bang » cao dang, cao tang, cao nang
so viet » hoc viet
cao ban » co ban, can ban, cao van
cao cay » cao cap, cho cay, tao cay
van cao » van dao, van bao, van hao
co soi » cot soi, co hoi, co loi
so hai » son hai, su hai, so ha
cay co » cac co, tay co, cay cong
o hai » co hai, o lai, _ hai

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 ban) OR (cao bang)) va ((cau xay) or (cau giay)) co soi viet nam ) or ((( chuong trinh sau luan van cao cay ((o hai) or (so hai)) viet nam ) or ( chuong trinh sau luan van cao cay co so viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh ((cao ban) OR (cao bang)) va ((cau xay) OR (cau giay)) co soi viet nam ) OR ((( chuong trinh sau luan van cao cay ((o hai) OR (so hai)) viet nam ) OR ( chuong trinh sau luan van cao cay co so viet nam )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( cong trinh ((cao ban) OR (cao bang)) va ((cau xay) or (cau giay)) co soi viet nam ) or ((( chuong trinh sau luan van cao cay ((o hai) or (so hai)) viet nam ) or ( chuong trinh sau luan van cao cay co so viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh ((cao ban) OR (cao bang)) va ((cau xay) or (cau giay)) co soi viet nam ) or ((( chuong trinh sau luan van cao cay ((o hai) or (so hai)) viet nam ) or ( chuong trinh sau luan van cao cay co so viet nam ))))*.