@misc{Engelmann_Rudolf_Abhandlungen_1876,
 author={Engelmann, Rudolf},
 address={Leipzig},
 howpublished={online},
 year={1876},
 publisher={Verlag von Wilhelm Engelmann},
 language={ger},
 title={Abhandlungen von Friedrich Wilhelm Bessel. Bd. 2},
 keywords={astronomical instruments, stellar astronomy},
}