This series comprises research materials for different projects related to Wilfred. A significant portion of this series includes bibliographic note cards composed by Stein. Other materials include photographs of Wilfred's artwork and studio, articles on Wilfred, writings by Wilfred, including his manuscript, Lumia, the Art of Light, and chronologies and lists of Wilfred's artwork compiled by Stein and/or Wilfred. There is also information on other kinetic light artists, including Frank Malina and Nicolas Schöffer. Materials are arranged alphabetically.