They're the primary two publications with the "Moderný Pračlovek" series (Modern day Caveman). The leading strategy was to represent caveman drawings in a quite simple way and items that ended up utilised at that time... but will also inside our days. The first one — “Kuchyňa Pračloveka” (Caveman's Kitchen area) https://maplepublishers.com/blog/how-to-start-your-career-as-a-fiction-writer-by-self-publishing-a-book/