Dense gas in nearby galaxies - XV. Hot ammonia in NGC 253, Maffei 2 and IC 342 R. Mauersberger, C. Henkel, A. Weiß, A. B. Peck and Y. Hagiwara A&A, 403 2 (2003) 561-571 Published online: 06 May 2003 DOI: 10.1051/0004-6361:20030386