These are definitely the 1st two publications with the "Modern dayý Pračlovek" series (Contemporary Caveman). The key strategy was to symbolize caveman drawings within a very simple way and products which were used at that time... but in addition in our times. The very first one particular — “Kuchyňa Pračloveka” https://maplepublishers.com/blog/what-newness-you-can-add-in-your-creative-book-cover-design/