Não informado. (2018). Progressus: Engineering progress. Handelsblatt GmbH.
Lua i Stíl Chicago (17ú heag.)Não informado. Progressus: Engineering Progress. Dusseldorf, Alemanha: Handelsblatt GmbH, 2018.
Lua MLA (8ú heag.)Não informado. Progressus: Engineering Progress. Handelsblatt GmbH, 2018.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.