@book
{TN_libero_mab2,
author = {
Canu, Ferdinand
AND
Bassler, Ray S.
},
title = {
North American early Tertiary Bryozoa
},
publisher = {Government Printing Office},
year = {1920-},
booktitle = {Bulletin United States National Museum},
address = {
Washington
},
url = {
http://slubdd.de/katalog?TN_libero_mab2
}
}