My son just read and reviewed Ptooma Productions Complete Glock Reference Guide.
In conclusion, if you own a Glock, your police department issues a Glock, or you work on Glocks for other people, you need this book! Here is the link to amazon.com to buy it. You will not be disappointed!
He liked it. And I’d note that my Glock 35 now has a nice sweet new trigger that he put in it, with this book as his guide. It is also available locally at Sportsman’s Warehouse.