Quartos pl. : of Quarto

Example:
How do I cite one of Shakespeare's Quartos in a research paper?

Taxonomy
four leaves, quarto edition, Gutenberg Bible, octavo, free encyclopedia, pamphlet, sheets, Shakespeare quartos, Search, sheet of paper, second quarto, Q1, gatherings, two times, leaf, fragment, bibliographers, demy.

Defination from the web:
quartos which were printed before the Gutenberg Bible. ... Bibliographer Alfred W. Pollard named those editions Bad quartos, and it is speculated that they may have been produced, not from manuscript ...