Made available in DSpace on 2015-05-12T17:12:20Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 6003989.PDF: 3203363 bytes, checksum: 4ba24d524f3308160d591495aaf32e04 (MD5) Previous issue date: 1960