There are a variety of Shadow comics and newspaper strips that have been put out. I managed to get the Crime Classics series, and some of the DC comics, but there are a number of others I have not gotten yet, mainly due to their rather high price.
Crime Classics 1
Crime Classics 2
Crime Classics 3
Crime Classics 4
Crime Classics 5
Crime Classics 6
Crime Classics 7
Crime Classics 8
Crime Classics 9
Crime Classics 10
Crime Classics 11
Crime Classics 12
Crime Classics 13
DC series storyline 1
DC series storyline 2
DC series storyline 3
Blood & Judgment
In the Coils of Leviathan