<a href="https://en.wikipedia.org/wiki/Achille_Compagnoni" class="extiw" title="w:Achille Compagnoni">Achille Compagnoni</a> on the summit of <a href="https://en.wikipedia.org/wiki/K2" class="extiw" title="w:K2">K2</a>, using oxigen mask.
<a href="https://en.wikipedia.org/wiki/Lino_Lacedelli" class="extiw" title="w:Lino Lacedelli">Lino Lacedelli</a>
1954-07-31
AAVV, Italienische Karakorum-Expedition 1954, <i>Berge der Welt</i>, vol. 10, pag. 39-72 (1955)