Most of these are cataloging errors for authors who may or may not have a Jr. in their name. (Numbering begins at 5 in case there is or will be anyone who actually uses "Jr." as a pseudonym.)
5. Great Science Fiction About Doctors was edited by Groff Conklin.
6. Outcast (Prima's Official Strategy Guide) is by Joel Durham Jr.
7. The Child Under Six is by James L. Hymes, also known as James L. Hymes Jr.
8. Critical Literacy: What Every American Needs to Know is by Eugene F. Provenzo Jr.
9. Kelland is by Paul G. Bens Jr.
10. The Vitamins, Third Edition is by Gerald F. Combs Jr.
11. Torts: Cases and Materials, 2nd Edition is by James A. Henderson Jr. ("James A. Henderson (1)" on LibraryThing) and Aaron D. Twerski.
12. Eldridge Tide and Pilot Book 2008 is by Robert Eldridge White, Jr. and Linda Foster White.
13. Millemondi Inverno 1999: Dimensioni vietate is an Italian anthology with works by P. Kettridge Jr., Frederic Brown, and Stefano Di Marino.
14. Isaiah: God Saves Sinners is by Raymond C. Ortlund Jr.