I came across a NACA summary [paper](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930093761.pdf) on the past 5 years of afterburner development and started reading cause it seemed interesting. However, a couple of pages in I scrolled back up and realized that it was written in 1956. How much have afterburners changed since then and would the information contained in the article still be relevant?