can anyone tell me in which books the spirits of belzazel, falkorath and alkyzub are mentioned.
Twenty seconds on Google shows it to be John Dee's 'LIBELLUS VENERI NIGRO SACER".
Owner and Editor
after 20 mins on google i could not find him!
There is a translation of the 'Sacred Book of Black Venus' or Tuba Veneris as it is also called, by Teresa Burns & Nancy Turner given in the Journal of the Western Mystery Tradition No. 12 Vol. 2 Vernal Equinox 2007. In the same issue is commentary on the possible provenance of the grimoire (in the vein of the Key of Solomon & Agrippa). It is available on-line but be careful the last time I looked there was one of those odd scams that tries to put a virus/worm or whatever on your computer.
The connection with John Dee is most likely spurious.
If you cannot get the translation then feel free to email me and I'll send you a copy.