Não informado. Philips Research Reports. Philips Gloeilampenfabrieken, Research Laboratory.
Chicago-referens (17:e uppl.)Não informado. Philips Research Reports. Eindhoven, Holanda: Philips Gloeilampenfabrieken, Research Laboratory.
MLA-referens (8:e uppl.)Não informado. Philips Research Reports. Philips Gloeilampenfabrieken, Research Laboratory.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.