@1
1 a3 is named after the German Adolf Anderssen
https://en.wikipedia.org/wiki/Adolf_Anderssen
There is also a more recent Swedish grandmaster Ulf Andersson
https://en.wikipedia.org/wiki/Ulf_Andersson
1 b3 is named after the Danish grandmaster Bent Larsen
https://en.wikipedia.org/wiki/Bent_Larsen
So -son is Swedish and -sen is German/Danish.
At times, I'm getting confused, as some say this and others say that.
1. a3 is the Anderssen opening or Andersson?
1. b3 is Larsen or Larson?
https://www.chess.com/lessons/offbeat-openings-2 uses "...son", while wiki uses "...sen"
How to get it right?