At this time, the stories which make up The Parasomnic Chronicles are available exclusively in digital formats, sold from many online stores, including:
Smashwords — Smashwords offers ebooks in a variety of formats, allowing books purchased here to be read on all sorts of e-reader devices and apps, including Kindle, Nook, and more. They also offer PDF versions and the ability to read a book directly in your web browser, so if you don’t have a dedicated app or device for ebooks, you can still get reading right away online.
Amazon — Amazon is home to the Kindle Store, and is a great choice if you prefer to use a Kindle handheld or app for your ebooks.
Barnes & Noble — Barnes & Noble is the developer of the Nook e-reader, and their webstore is optimized for delivering ebooks to Nook devices.
Apple Books — Stories from The Parasomnic Chronicles are available for in-app purchase on Apple Books, for Mac computers and iOS devices.