<code>
@Book{bogatz1988mikrorechner,
 author = {Bogatz, Andreas},
 title = {Mikrorechner in der Amateurmesstechnik},
 publisher = {Militärverl. d. Dt. Demokrat. Republik},
 year = {1988},
 address = {Berlin, DDR},
 isbn = {3327005532},
 sign = {11/00115},
 gbv = {54.26},
 rvk = {},
 url = {},
 thumb = {http://www.booklooker.de/images/cover/user/0018/1193/Ym4wMDA2.jpg}
}
@Manual{robotron1986handbuch-1715w,
 author = {Autorenkollektiv},
 title = {Handbuch 1715/1715W},
 institution = {VEB Robotron Büromaschinenwerk Sömmerda},
 year = {1986},
 address = {Sömmerda, DDR},
 sign = {},
 gbv = {54.26},
 rvk = {},
 url = {http://www.sax.de/~zander/pc1715/doku/pc_manu.pdf},
 thumb = {http://www.sax.de/~zander/pc1715/bilder/1715wman.jpg}
}
@Manual{robotron1986handbuch-1715,
 author = {Autorenkollektiv},
 title = {Handbuch 1715},
 institution = {VEB Robotron Büromaschinenwerk Sömmerda},
 year = {1986},
 address = {Sömmerda, DDR},
 sign = {},
 gbv = {54.26},
 rvk = {},
 url = {http://www.sax.de/~zander/pc1715/doku/pc_hb.pdf},
 thumb = {http://www.sax.de/~zander/pc1715/bilder/1715hb.jpg}
}
</code>