They're the initial two publications with the "Present dayý Pračlovek" sequence (Modern Caveman). The most crucial thought was to symbolize caveman drawings in a very quite simple way and products which were being used at that time... and also inside our times. The first one — “Kuchyňa Pračloveka” (Caveman's Kitchen) https://maplepublishers.com/blog/what-are-the-top-book-cover-trends-awaits-us-this-year/