"Street Art is by far the most controversial art form of our times. It takes place in the street, far away from galleries and at the verge of legality. Nevertheless or maybe because of this, it fascinates and is developing into an art form that increasingly gains acceptance. The sprayed or glued pictures that can be foundprimarily in big cities on house walls and rail cars areanonymous, provocative, and non-academic. They often, but not always, pick up political protest and sometimes are part of an attempt to bring poetry to the city.24 motifs are each depicted on two cards. Whoever turns up two identical motifs may put them on his or her pile of cards." Это и многое другое вы найдете в книге Memo Street Art (Johannes Stahl)