Pokémon Adventures volume 51 is the eighth and final volume in the Black & White chapter. Coincidentally, the same volume was also released by VIZ Media earlier in the same month on October 6. At this time, neither publisher has announced a release of Volume 52, the first volume in the Black 2 & White 2 chapter.
Pokémon Adventures XY volume 2 is Shogakukan Asia's English translation of the mini-volumes of the X & Y chapter which are released by Shogakukan in Japan. This follows the release of Volume 1 in May. Unlike Shogakukan Asia, VIZ Media has opted for their own mini-volumes, much like their mini-volumes of the Black & White chapter. VIZ Media's most recent mini-volume was Pokémon XY volume 4, released in September, with Volume 5 due to be released in December.