*{{Literatur |Autor=George Adams |Titel=Physical and Ethereal Spaces |Hrsg= |Sammelwerk= |Band= |Nummer= |Auflage= |Verlag= |Ort=London |Datum=1965 |Sprache=en |ISBN= |Seiten= |Online=https://archive.org/stream/AdamsGeorgePhysicalAndEtherealSpaces/Adams%20George%20-%20Physical%20and%20ethereal%20spaces_djvu.txt}} | *{{Literatur |Autor=George Adams |Titel=Physical and Ethereal Spaces |Hrsg= |Sammelwerk= |Band= |Nummer= |Auflage= |Verlag= |Ort=London |Datum=1965 |Sprache=en |ISBN= |Seiten= |Online=https://archive.org/stream/AdamsGeorgePhysicalAndEtherealSpaces/Adams%20George%20-%20Physical%20and%20ethereal%20spaces_djvu.txt}} |