Papers relating to bird calls and bird sound [Former reference: Item 3460], comprising: 'Human Imitation of Bird Sound', an essay and discography by Jeffery Boswall, Robert Barton and Peter Copeland, reprinted from Recorded Sound 83, with circular covering letter and a photocopy of the article annotated by Boswall, [1983?] 2 leaflets about Olt's bird callers, n.d.…