c. 1922 Nude Lady – Probably his wife (they married in 1922) & fellow student Marie van Veen. Mixed technique (Pastel & Ink) on paper signed “Johan D.” on lower left part. Provenance : Frankfurt private collection & Bordeaux collection. Very comparable to the c.1922-25 Horseback riders Ink, pen 21x27cm Christies Amsterdam 12-6-2001 lot 23. The 1920s are the most fascinating part of his long and rich career & most looked after drawings. Dijkstra was one of the founders of the Groninger Kunstkring De Ploeg in 1918. Stimulated by De Ploeg's innovative artistic élan, he developed into one of the most important graphic artists within the art circle.