Thanks for getting back to me so quickly!
It's from THIS site! https://fiddlerman.com/wp-cont.....__Op32.pdf
I have the Sitt Etudes in book form (I like books better than downloads), and in Bar 41, I have the 0 over the A in the fourth beat. To be honest, I don't really like the first Etude, I'm currently working on #6, which I like because I have to really work at it so that I don't annoy my neighbors too much!