ACKNOWLEDGEMENTS

     The contributions of Miss Josephine L. Walkowicz and her staff in the preparation
and checking of items for the bibliography, and of Mrs. Betty J. Anderson, Mrs. Helen B.
Grantham, and Mrs. Anna K. Smilow in the typing and editing of the manuscript are
gratefully acknowledged.  The courtesy of Miss Thy~1is Williams. Mr. Joseph Becker,
Mr. Herbert Ohlman, and the late Hans Peter Luhn in making available unpublished
materials is also gratefully acknowledged.




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