I found an old Pokémon DP anime novelization I got at a Scholastic Book Fair back in elementary school. Bulbapedia doesn't seem to have much on them.

[Red Knight]

Specifically, I have a double feature. The "front" side is "Pokémon Academy" by Katherine Fang, which adapts the events of the Pokémon Summer Academy arc, while the "back" side is "The Lost Riolu" by Helena Mayer, which adapts the two-part episode "Pokémon Ranger and the Kidnapped Riolu!" The book also came with a page of temporary tattoos, which I never used because I was raised Mormon and thus taught that tattoos were immodest and sinful. (I think temporary tattoos technically aren't considered sinful because they are designed to not be permanent, but elementary school aged me did not understand the significance of this distinction.) Here I have attached pictures of both covers, the spine, and the page of tattoos.

Spoiler: images, sorry I don't know how to format them better

As a disclaimer, I have not seen any of the relevant episodes of the anime. But based on my research, "Pokémon Academy" features a heavily abridged version of the episodes it adapts, even completely omitting the events of the second episode of the four-episode arc, "Up Close and Personable!". Additionally, I did not see Katherine Fang credited for writing "Pokémon Academy" anywhere in the book, while Helena Mayer is credited on the inside front cover of "The Lost Riolu." This may warrant further investigation on my part. (Also, I should maybe actually watch the anime episodes in question.)