It's irrelevant that it's from New
York - distinguishing that it's from one city in particular makes no sense. And there's still no such word as "Newyorkian". The correct way to say it would be "from the US". You could add "(published in New
York)" if you were desperate to be more specific, but as I said it's really irrelevant which city it was published in.
The word you are looking for is "State".