This info was submitted by reader Jan de Vries on May 31, 2014. Note, I was unable to access an English translation via Google Translate, so we may have to depend upon Jan's summary for now.
"I found some entries about the Parker-Hulme case in old Dutch newspapers that you can find on the internet at http://www.kb.nl/kranten, a website of the National Dutch Library that contains also a collection of all old Dutch newspapers.
If you put in the name Pauline Parker, you get some entries from Dutch papers of July and August 1954, from Nieuwsblad van het Noorden (Northern Newspaper). It tells on July 17 something about the trial, a small entry, not more. But there is question of Juliet & Pauline who leave the courtroom at the end of the day "cheerfully chatting with one another" and showing "no sign of remorse". And in an entry of August in the Limburgs Dagblad (another newspaper) about the verdict, there is mention of the Fourth World, wanting to become novel writers and the diary mentioning The Day of the Happy Event. The paper concludes with the claim of the defense that "the children are insane".
Unfortunately I cannot copy the original entries from the site. But you can find them yourself on http://www.kb.nl/kranten.