Perhaps you should try some spelling variations:
trinh cao » trinh chao, trinh cau, tinh cao
trinh sau » trinh san, trinh cau, trinh su
doi viet » dai viet, oi viet, do viet
soi viet » so viet, oi viet, noi viet
trinh co » trinh do, trinh cong, trinh hoa
hoi viet » hai viet, oi viet, thai viet
cac tay » cac cay, cac tac, cac tai
tay cot » tay mot, tay cong, tay vuot
sau lan » dau luan
cau tay » cau tao, cau xay, cam tay
lan va » luan va, lanh va, lan van
va cau » van cau, va dau, va cao
tay co » ty co, cay co, tay o
co hoi » co hoc, co loi

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

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