Yes....Al Angerman's article was a follow up to some of the work done by Rick Hornbeck and Creighton Audette. I believe the Angerman article was in '93
German Salazar trod similar ground more recently.
IIRC, he also included spark photography (as did Audette) or long exposure photography (i forget which) to image the prime flame front.
These days you’ll ha em to be motivated to find his work as he pulled much of it from online outlets.
