These are Volume 2 and 3 of Gabriel Dropout and the Dengeki Daioh G magazine Chapters. Volume 1 was done by Morally Bankrupt Translations and you can find it on their website.
In other news, Gabriel Dropout is getting an anime beginning this January. It’s being produced by Doga Kobo and animated by the same team behind Himouto! Umaru-chan. Sadly, this means Volume 4 has been pushed back to January to promote the anime (or perhaps the anime is promoting Volume 4), but we have 2 Dengeki Daioh G that have yet to be released, so I guess that will fill the spot.
Dengeki Daioh G Magazine Chapters (28-33)