In the archive of the place where the child was born, for all children born in the Netherlands there's a Birthrecord...and sometimes in newspapers of course . Finding a record for someone born after 1933 can be very difficult though because Birth records in the Netherlands only become public after 100 years ...but you can check sometimes at archives which records are available and for what period and place like this one archief Rivierenland for example , for deaths the time is abt 75 year I think so maybe you could find a death record ?