They're the first two publications with the "Contemporaryý Pračlovek" series (Contemporary Caveman). The key idea was to represent caveman drawings inside of a quite simple way and products which were being employed At the moment... but also in our times. The very first 1 — “Kuchyňa Pračloveka” (Caveman's Kitchen area) https://maplepublishers.com/blog/how-can-you-become-a-thriving-author-while-book-self-publishing-london/