Perhaps you should try some spelling variations:
trinh chat » tinh chat, trinh luat, trinh han
trinh cau » trinh chao, trinh han, trinh tai
trinh tu » trinh ky, trinh do
soi viet » hoi viet, oi viet, doi viet
chat dan » chat ban, chat ran, hat dan
cau dan » cau danh, cac dan, ca dan
cac bac » cac bai, cac ban, cac cach
cac cac » cac cach, ca cac, cac cam
so viet » hoc viet
cay nam » cay lam, tay nam, cai nam
cac cap » cao cap, cac cam, cac cau
va cay » va cao, va cai, va cau
co hoi » co loi
co soi » cot soi, co loi, co doi
cap co » cap cho, tap co, cap do
tu dan » tuc dan, tu ban, cu dan
dan va » doan va, dan ca, ban va

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 cau dan va cac cap co soi viet nam ) or ( cong trinh chat dan va cay nam ((co hoi) OR (co hoc)) viet nam ))) or ( cong trinh tu dan va ((cac cac) or (cac bac)) co so viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh cau dan va cac cap co soi viet nam ) OR ( cong trinh chat dan va cay nam ((co hoi) OR (co hoc)) viet nam ))) OR ( cong trinh tu dan va ((cac cac) OR (cac bac)) co so viet nam )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( cong trinh cau dan va cac cap co soi viet nam ) or ( cong trinh chat dan va cay nam ((co hoi) OR (co hoc)) viet nam ))) or ( cong trinh tu dan va ((cac cac) or (cac bac)) co so viet nam ))".
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh cau dan va cac cap co soi viet nam ) or ( cong trinh chat dan va cay nam ((co hoi) OR (co hoc)) viet nam ))) or ( cong trinh tu dan va ((cac cac) or (cac bac)) co so viet nam ))*.