They do seem to be crippling book search on purpose. Just yesterday I was looking for "PC Mag 1997 january Pentium MMX" and Google refused to return PC Mag 7 Jan 1997 issue results, whats even more weird clicking "browse all issues" returns

    The requested URL /books/serial/ISSN:08888507?rview=1 was not found on this server

but "About this magazine" will happily give you a list of all scanned issues :o and opening january one will let you search it and will return positive results.