X-Factor (2005) (Collected Editions) is a 23-book series with 20 primary works first released in 2005 with contributions by Peter David, Ryan Sook, and 5 others.
2006 • 8 Readers • 144 pages • 3.5
2007 • 3 Readers • 120 pages • 4
2008 • 3 Readers • 168 pages • 4
2009 • 1 Reader • 168 pages • 5
2010 • 3 Readers • 128 pages • 3.5
2011 • 3 Readers • 144 pages • 4
2011 • 3 Readers • 144 pages • 4
2011 • 3 Readers • 112 pages • 4.5
2012 • 3 Readers • 112 pages • 3.5
2012 • 3 Readers • 112 pages • 3.5
2012 • 3 Readers • 96 pages • 4
2013 • 3 Readers • 112 pages • 4
2013 • 2 Readers • 96 pages • 3.5
2013 • 2 Readers • 160 pages • 4
2014 • 2 Readers • 4
2009 • 2 Readers • 4