Logo of defunct German commuter airline DLT, shortly after its split-up from OLT, ca. 1974
Unknown author<span style="display: none;">Unknown author</span>
Karl-Dieter Seifert, <i>Der deutsche Luftverkehr 1955–2000, Weltverkehr, Liberalisierung, Globalisierung</i>, Bonn 2001, p. 104.