B. S. Ghast
From Tardis Wiki, the free Doctor Who reference
Compendium on Ghost Physics by a B. S. Ghast was one of the books kept on the Dr Smith shelf in P.R.O.B.E. HQ contemporaneously with Box's years of "residence" there. (PROSE: Out of the Box)
Behind the scenes
As stated by the copyright page of the Out of the Shadows anthology, the Compendium on Ghost Physics and its author Beauregard S. Ghast were the preexisting, non-DWU creations of writer Myrriah Hopkins, referenced in the story with Hopkins' permission. Ghast's first name appears on the said copyright page, but only his initials are used in the actual text of Out of the Box.