The book shown as #16A is actually Spider-Man, vol. 2 [MX] #13D. All six parts of Sitting In A Tree were published as Spider-Man, vol. 2 [MX] #12-17. Spider-Man (2016-2018) - Colexiono
Panini published book #16B, a reprint of the American issue of Spider-Gwen, vol. 2 #16. This listing should be separate from the Spider-Gwen, vol. 2 [MX] that I just posted in Core | Missing that was published by Smash Comics for Marvel Mexico. In those books, Spider-Gwen #16 is a reprint of US Spider-Gwen #10.