International Picture Language: The First Rules of Isotype : Neurath, Otto, 1882-1945
▻https://archive.org/details/internationalpic00neur/page/12/mode/2up
International Picture Language: The First Rules of Isotype : Neurath, Otto, 1882-1945
▻https://archive.org/details/internationalpic00neur/page/12/mode/2up
cf. ▻https://seenthis.net/messages/949922 (visionscarto.net)