Perhaps you should try some spelling variations:
trinh khau » trinh khai, trinh kham, trinh khac
khau luan » khoa luan, phap luan, pham luan
trinh nha » trinh phan, trinh chat, trinh chao
trinh cao » trinh chao, trinh co, trinh cau
co nguoi » cho nguoi, con nguoi, o nguoi
dot viet » dat viet, do viet, doc viet
nha hang » nha sang, ngan hang, nhat hanh
hai viet » thai viet, mai viet, tai viet
cao luan » cao lan, cao quan, cao xuan
tac cay » tac can, tao cay, cac cay
cac mau » cam mau, sach mau
cac cau » bac cau, ca cau, cac cam
cua cau » chua cau, cua cac, cua chu
va tac » va cac
van ca » van cau, van cua, dan ca
cay co » cac co, tay co, cay cong
ca cay » cua cay, cac cay, ca cac
co hai » co dai, co hoi, o 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 luan van ((((cac cau) or (cua cau))) or (cac mau)) co hai viet nam ) or ((( cong trinh khau luan van ca cay co dot viet nam ) or ( cong trinh nha hang va tac cay co nguoi viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh cao luan van ((((cac cau) OR (cua cau))) OR (cac mau)) co hai viet nam ) OR ((( cong trinh khau luan van ca cay co dot viet nam ) OR ( cong trinh nha hang va tac cay co nguoi viet nam )))).
• Adding a wildcard symbol may retrieve word variants: (( cong trinh cao luan van ((((cac cau) or (cua cau))) or (cac mau)) co hai viet nam ) or ((( cong trinh khau luan van ca cay co dot viet nam ) or ( cong trinh nha hang va tac cay co nguoi viet nam ))))*.