A scholarly resource must be written by a scholar - an expert in the field, usually with a PhD or equivalent qualifications. Scholarly resources usually tell you about the author, so that you can assess whether s/he is a reliable expert on the information presented.
Walkmeter uses GPS to measure the distance of your walks and hikes outdoors. It functions much like a stopwatch. Open the app, tap Start, and use Lap when you want to log an interval. It maps your walk, and you can view time, speed, distance, and pace as you walk.
If you use your step count over a longer known walking distance, it should give a more accurate average stride length measurement than the short walk method. Here are two suggestions. Use a football field, which is 300 feet from goal line to goal line.