No worries at all, don't think I was the first to organize the exercises that way anyways and if I was oh well, I didn't see any other way to organize all of those exercises anyways, so happy the layout works for you and that you like it!
Looking good, especially those spheres! Wow you can really feel their volume. Also nice gestures, those look great! Awesome work as always! and I think your color blends are looking good, takes a bit to get used to doing that, I still struggle with it so don't sweat it too much just keep practicing.
For the lineart studies, one way I found that helped me find a few to study initially was looking on https://characterdesignreferences.com/ If you go to the Artist of the Week tab, they have galleries full of character artist's work. Helped me identify some artists whose style I wanted to study and good for general inspiration.
Otherwise, outside of artbooks/comics, when I'm looking up references I try to search for concept sketches rather than concept art, sometimes that works and pulls up different results, but as others have said, concept art is pretty painterly generally. But worth a shot if you have a character you really want to study and can't find it through a normal search.
