PLOOS van AMSTEL, Jaap (1926-2022). (No title). (N.d.). Drawing in pencil and chalk. 340 x 440 mm. Signed in pencil. Under passepartout. -- Elbert PLOOS VAN AMSTEL (1954-). (No title). 1988. Drawing in black chalk & grey wash. 265 x 350 mm. Signed and dated in pencil. Under passepartout. -- (2).