To read ePub files use Adobe Digital Edition 4.5
A latest edition to PER/PELJ is ePub files. In order to read these files on your device, you need to ensure that you have an reader capable of opening ePub files. An ePub Reader can be installed on your device, or downloaded from your devices' app store. Adobe Digital Editions 4.5 can be downloaded here.
For more information on ePub software, see https://en.wikipedia.org/wiki/EPUB#Reading_software