[826] In folĭo (lat.), in Folioformat (s. Folio).
Adelung-1793: Folio
Brockhaus-1911: In folio · Folio
Herder-1854: In folio
Meyers-1905: Folĭo
Pierer-1857: Partes folio · Recto folĭo · Folio · Folĭo