>>64097897
>>64101685
>Chuck Taylor magazines early 80s
Probably this.
It was never in any of the official/academic published book references such as Jane's back then, nor was it in military manuals.
And it never came into wider-popular use in the firearm world (apart from the select readership of SOF, which was much smaller and niche-focused than, say for example, Guns & Ammo magazine) until the post-internet 2010s.
As discussed upthread, throughout the Cold War era select fire rifles were Automatic Rifles