Copyright and related rights to these illustrations are waived via CC0 (https://creativecommons.org/publicdomain/zero/1.0/) Nevertheless we want to thank the very talented illustrator who made the design: https://www.fiverr.com/gasacreative/draw-detail-illustration-for-t-shirt-design and Joe Morrison for coordinating this creation. T-shirts and pullover hoodie can be ordered at https://teespring.com/gdal