"Chillogy" was the only story completely unassociated with either R.L. Stine's Goosebumps books or short stories ("More Monster Blood" did have some ties, if indirect ones, to the book Monster Blood II) - and the only one which actually did not include Stine as a writer.
A few Goosebumps books can be seen on Matthew's shelf: A Shocker on Shock Street when his mom enters and Diary of a Mad Mummy during the last scene in it.