Pavlov, IvanAutograph letter signed, one pages, 8 x 8,75 inch (lined paper affixed on cardboard), 27. 11. 1929, in German, to the Berlin physiologist Adolf Bickel, who had congratulated him on his 80th birthday in an article in the scientific magazine `Archiv fr Verdauungskrankheiten` (published by Pavlov), written and signed in black ink "I. Pawlow", attractively mounted (removable) for fine display with a photograph, shows Ivan Pavlov in a head and shoulders