books.google.de - The book is the first comprehensive encyclopedia of Western ideograms ever published, unique in its search systems, that allows the reader to locate a symbol by defining just four of its visual characteristics. It is about our graphic cultural heritage as expressed in subway graffiti, fighter jets' signs...http://books.google.de/books/about/Thought_Signs.html?hl=de&id=8s1Gl2X-DlgC&utm_source=gb-gplus-shareThought Signs
