Não informado. Philips Research Reports. Philips Gloeilampenfabrieken, Research Laboratory.
Lua i Stíl Chicago (17ú heag.)Não informado. Philips Research Reports. Eindhoven, Holanda: Philips Gloeilampenfabrieken, Research Laboratory.
Lua MLA (8ú heag.)Não informado. Philips Research Reports. Philips Gloeilampenfabrieken, Research Laboratory.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.