As near as I can tell, the sixth volume of Pogo: The Complete Syndicated Comic Strips is now everywhere it's supposed to be except for stores that have sold out of their first delivery. If you live in my area and you order it via Amazon Prime in the next hour, they will deliver your copy today. Can't ask for much more available than that. (And of course, the Kindle edition will come to you via instant delivery but I think this is one of those books that's more wonderful in your hands than on your tablet.)
Over on its Amazon page, you can order or if you're not ready to do that, you can read a large sample of this edition. I think it's the best newspaper strip ever done. If you think that distinction belongs to Peanuts or Doonesbury or Krazy Kat or Ziggy…fine. We needn't mud-wrestle except maybe if you think Ziggy. But even that's fine…and a collection of the second-best strip or the third-best strip is still a wonderful thing to own. Own one soon. Better still, own all of them.