For my own reference: links thrown up by my search above:
https://www.soas.ac.uk/courseunits/155900901.html - good bibliography, I have read some already.
http://en.wikipedia.org/wiki/Prose_poetry - list of French and German writers I should have read but haven't! I'm not a slacker, just someone who liked sitting on my rug on the grass in the sunshine, chatting.
There are plenty more, but this is quite enough. Another entry gave some paragraphs from a book I have only 2 feet away from where I am sitting right now.
http://www.poetrypreviews.com/poets/prosepoem.html - some English writers of the pp, plus links.
http://magmapoetry.com/archive/magma-42/articles/poetry-in-practice-are-prose-poems-poems/ - anything from Magma is excellent.
There were 2 sentences which explained exactly what I wanted to know. When I find them I will quote them.
Short sentences in separate lines.