@misc{becker_13co_emission_1991, 
author={Becker, R., Freudling, W.},
title={13CO emission in the irregular galaxy NGC 55 and in the IR-luminous galaxy NGC 3256},
year={1991},
howpublished = {journal article},
note = {Becker, R.; Freudling, W.: 13CO emission in the irregular galaxy NGC 55 and in the IR-luminous galaxy NGC 3256. Astronomy and Astrophysics. 1991. vol. 251, 454ff..}}