I use this coding reference: It's served me very well for the last 15 years. http://scriptures.byu.edu/gettalk.php?ID=4 with this pen: http://www.amazon.com/Pentel-Automatic-Pencil-Assorted-PH158/dp/B001PMJZ3K/ref=sr_1_3?ie=UTF8&qid=1453106438&sr=8-3&keywords=pentel+colored+pencils