The Apocrypha and Pseudepigrapha of the Old Testament, edited by R.H. Charles (1913 edition), is a collection of Jewish religious writings, mainly from the centuries leading up to the New Testament events. They are arguably the most important non-biblical documents for the historical and cultural background studies of popular religion in New Testament times. The early church writers made use of these documents, and the New Testament even quotes or alludes to a few of them. The Epistle of Jude, for example, contains allusions to the Assumption of Moses.
The Logos edition contains some exciting enhancements to make this work even more accessible and useful. Charles's in-depth commentary/notes (appearing in the print edition as footnotes—see page scan below) are broken out into a separate 'commentary' volume in the electronic edition. This makes it easy to open the text and commentary side-by-side so they scroll together as you read through the Charles text (or any other text such as the KJV Apocrypha, for example). Where Charles included a critical apparatus (e.g., Fourth Ezra—see screenshot below), it, too, is broken out as a separate volume.
As with every Libronix-compatible resource, all Bible references are hotspots that open your preferred Bible version to the specified passage. Abbreviations and annotation symbols are decoded via pop-ups that appear when you hover the mouse over the abbreviation or symbol. Inter-textual links are also hotspots that jump you to the resource referenced (e.g., clicking a footnote marker in The Assumption of Moses will open the accompanying commentary to that point).