<br>Construction plan of the bridge of <a href="https://en.wikipedia.org/wiki/Robert_Maillart" class="extiw" title="en:Robert Maillart">Robert Maillart</a> across the Aar in Innertkirchen, 1934; Berne, Switzerland.
Robert Maillart (reworked and uploaded by <a href="//commons.wikimedia.org/wiki/User:Chriusha" title="User:Chriusha">Хрюша</a>, 2011-09-25)
1934
<i>Einige neuere Eisenbetonbrücken</i>.  Schweizerische Bauzeitung (e-lib.ch), Heft 15 von 1936, Seite 159.