Comments/Ratings for a Single Item

Rating 7 out of 10 for Berkeleian Chess(1984): 'When a piece is unobserved it disappears from the board. An observed piece is one that is defended or notionally defended (in the case of a pinned piece) by another man.' --full write-up in 1994 Pritcard's ECV. 
Notes: 1) Nice idea 'Berkeleian' could apply widely, including to any of the 3000 CVPage games in general.
2) Presumptively classifiable here as 'modest cv', Berkeley theme is actually genuine mutator, unlike way-overworked sterile mixing-around or randomizing back rank of pre-existing games. (A fortiori, slight majority of CVPage games are propietarily at best half-creative new combinations of known elements, but the 100-member Carrera-Capablanca family fails even rising to that)
3) Tactically in real play, Berkeleian forces, whatever particular embodiment thereof, tend to group effectively together, like present games being played of Elephant Chess in CVPage Game Courier.
4) If we missed someone's using partly the Berkeley theme already, Berkeleian was not cited, or we would have noticed, so anyway this points to origination.

Is the book Encyclopedia of Chess Variants by David Pritchard available?  I
would like to buy a copy.  If it is not available from you, where might I
get a copy?  My e-mail address is [email protected].
Thank you.
Fred Feaster

See:

http://www.chessvariants.org/index/shopitem.php?itemid=CECV