Nudes | M.C. Escher, 1919-1921

M.C. Escher, Female Nude I, 1920

M.C. Escher, Seated Female Nude, 1921

M.C. Escher, Female Nude in a Landscape, 1920

M.C. Escher, Female Nude in Chair, 1920

M.C. Escher, Seated Female Nude III, 1920

Also: 

Reflections | M.C. Escher