<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>
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Gladys Fabre   and  Doris Wintgens Hötte (2009; ed.) <i>Van Doesburg &amp; the international avant-garde. Constructing a new world</i>, [London]: Tate Publishing, <a href="//commons.wikimedia.org/wiki/Special:BookSources/978-1-85437-872-9" title="Special:BookSources/978-1-85437-872-9">ISBN 978-1-85437-872-9</a>, ill. 19, p. 34.