<bdi><a href="https://en.wikipedia.org/wiki/en:Theo_van_Doesburg" class="extiw" title="w:en:Theo van Doesburg"><span title="Dutch architect, painter, draughtsman and writer (1883-1931)">Theo van Doesburg</span></a>
</bdi>
1915
Polano, Sergio (1979) <i>Theo van Doesburg. Scritti di arte e di architettura</i>, Roma: Officina Edizione, [p. 9], nr. 24.