National Central Library (Florence) in the context of "Liber Abaci"

Jacopo da Lentini, also known as Giacomo da Lentini or with the appellative Il Notaro, was an 13th-century Italian poet and inventor. He was a senior poet of the Sicilian School and was a notary at the court of the Holy Roman Emperor Frederick II. Jacopo is credited with the invention of the sonnet. His poetry was originally written in literary Sicilian, though it only survives in Tuscan.

Although some scholars believe that da Lentini's Italian poetry about courtly love was an adaptation of the Provençal poetry of the troubadours, William Baer argues that the first eight lines of the earliest Sicilian sonnets, rhymed ABABABAB, are identical to the eight-line Sicilian folksong stanza known as the Strambotto. Therefore, da Lentini, or whoever else invented the form, added two tercets to the Strambotto in order to create the 14-line Sicilian sonnet.

The Codex Magliabechiano is a pictorial Aztec codex created during the mid-16th century, in the early Spanish colonial period. It is representative of a set of codices known collectively as the Magliabechiano Group (others in the group include the Codex Tudela and the Codex Ixtlilxochitl). The Codex Magliabechiano is based on an earlier unknown codex, which is assumed to have been the prototype for the Magliabechiano Group. It is named after Antonio Magliabechi, a 17th-century Italian manuscript collector, and is held in the Biblioteca Nazionale Centrale, Florence, Italy.

It was created on European paper, with drawings and Spanish language text on both sides of each page. The Codex Magliabechiano is primarily a religious document. Various deities, indigenous religious rites, costumes, and cosmological beliefs are depicted. Its 92 pages are almost a glossary of cosmological and religious elements. The 52-year cycle is depicted, as well as the 20 day-names of the tonalpohualli, and the 18 monthly feasts.