They're the primary two publications for that "Moderný Pračlovek" collection (Modern Caveman). The key strategy was to symbolize caveman drawings in a very simple way and items that were being used At the moment... but will also inside our days. The 1st one particular — “Kuchyňa Pračloveka” (Caveman's Kitchen area) https://maplepublishers.com/blog/popular-self-publishing-trends-of-this-year/