Perhaps you should try some spelling variations:
trinh sau » trinh san, trinh cau, trinh su
cau giay » cuu giai, cac giai
hai viet » thai viet, mai viet, tai viet
sau luan » su luan, dau luan, sau lan
soi viet » hoi viet, oi viet, doi viet
cao ban » cao bang, co ban, cao van
can ban » van ban, toan ban
van hao » van dao, van ha, van bao
hao cay » tao cay, chau cay, hao cach
so viet » hoc viet
co soi » cot soi, co hoi, co loi
cay co » cac co, tay co, cay cong
cay o » cay mo, cay ot, cay so
o hai » co hai, so hai, o lai

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