Below are some great references that we think are great additions to your Umpiring Library of Reference Material.
Baseball Rules in Black & White
2018 High School Baseball Rules Edition 2018 NCAA College Baseball Rules Edition
This is a great reference book that explains and correlates High School Federation Baseball Rules and associates related rules for easy access. All rules are listed in alphabetical order, and any related rule reference is colocated for easy use.
If you are looking for something to help navigate the sometimes complex differences between High School Federation rules and MLB rules, this book is the ticket.
BASEBALL RULES IN BLACK AND WHITE PO Box 81
Willows, Ca 95988