The system of titles puts emphasis on the differentiation between the artist’s own titles and those given after the artist’s death. The artist’s title, if it exists, was provided first, followed by the title (in parentheses) given in 1957 by the artist’s mother Krystyna Wróblewska (1904–1994). If the former or the latter do not exist, the title, or titles, found in the literature of the subject were provided in square brackets. If a given work had never previously been exhibited or reproduced, the title provided in square brackets was given by the Foundation. In addition, for works on paper exploring similar themes, the Foundation provided numbers featured on the recto, given by the artist’s mother in 1957 on the occasion of cataloguing the artist’s oeuvre. The works include dates, if provided by the artist, works with dates provided by the artist’s mother were deemed undated.