bibliographical (adj.)

1670s, "the writing of books," from Greek bibliographia "the writing of books," from biblion "book" (see biblio-) + graphos "(something) drawn or written" (see -graphy).

The meaning "the study of books, authors, publications, etc.," is from 1803. The sense of "a list of books that form the literature of a subject" is attested by 1814. Related: Bibliographic.

compound adjectival word-forming element, usually interchangeable with -ic but sometimes with specialized sense (such as historic/historical, politic/political), Middle English, from Late Latin -icalis, from Latin -icus + -alis (see -al (1)). Probably it was needed because the forms in -ic often took on a noun sense (for example physic). Forms in -ical tend to be attested earlier in English than their twins in -ic.