Chronologically Lewis by Joel Heck (searchable resource of over 1000 pages of details of Lewis’ life)
Complete Works of C. S. Lewis in Chronological Order by Joel Heck (scroll down for searchable 25-page pdf)
Concordia Lutheran Seminary, Edmonton, Canada, YouTube Channel: C. S. Lewis lectures by Joel Heck
C. S. Lewis and the Craft of Communication by Steve Beebe
The Discovery Institute has Peter Kreeft's 1998 address "The Achievement of C. S. Lewis: A Millenial Assessment." Search or scroll down to section III to read The Battle of the Books. Lewis’s books argue which one is his center.
Essential C. S. Lewis by William O’Flaherty
Lanier Theological Library: C. S. Lewis Collection
Lewisiana by Arend Smilde
Marion E. Wade Center at Wheaton College
Marion E. Wade Center at Wheaton College: YouTube Channel
That Hideous CS Lewis Substack by Brian Shepherd