Helff, S., & Michels, S. (2018). Global photographies: Memory - history - archives / Sissy Helff, Stefanie Michels (eds.). transcript.
Lua i Stíl Chicago (17ú heag.)Helff, Sissy, agus Stefanie Michels. Global Photographies: Memory - History - Archives / Sissy Helff, Stefanie Michels (eds.). Bielefeld: transcript, 2018.
Lua MLA (8ú heag.)Helff, Sissy, agus Stefanie Michels. Global Photographies: Memory - History - Archives / Sissy Helff, Stefanie Michels (eds.). transcript, 2018.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.