  We go through Bohr's talk about complementary features of quantum theory at
the Volta Conference in September 1927, by collating a manuscript that Bohr
wrote in Como with the unpublished stenographic report of his talk. We conclude
- also with the help of some unpublished letters - that Bohr gave a very
concise speech in September. The formulation of his ideas became fully
developed only between the fifth Solvay Conference, in Brussels in October, and
early 1928. The unpublished stenographic reports of the Solvay Conference
suggest that we reconsider the role that discussions with his colleagues
possibly had on Bohr's final presentation of the complementary sides of atomic
physics in his 1928 papers.
