Three-view drawing of Blériot-SPAD S.33 <i>bis</i> (here referred to as "Spad-Herbemont").
<i>Flight</i>
1921-07-07
<a rel="nofollow" class="external text" href="https://www.flightglobal.com/pdfarchive/view/1921/1921%20-%200461.html"><i>Flight</i>, vol. XIII, no. 27, p. 461, "The Spad 'Berline' S.33 <i>bis</i>".</a>