In 1967, the São Paulo 9 - Environment United States: 1957-1967 in Brazil showed Gill's works with artists such as Andy Warhol and Edward Hopper.
1967 zeigte die „São Paulo 9 – Environment USA: 1957–1967“ in Brasilien Gills Kunstwerke zusammen mit Künstlern wie Andy Warhol und Edward Hopper.