Leonardologist’s Reference Style or solution of the Advent Riddle

There was another hard nut to crack this year. Once again, courageous people took up the challenge bridging the time span of five centuries to the spirit and work of Leonardo da Vinci.
Many thanks for the solutions sent in, all of which testify to an intense and creative involvement. Congratulations to Pasadena (California) for the winner!
Using the example of da Vinci’s notes, scattered around the world and rebound in different codices, we wanted to demonstrate how difficult is searching for manuscripts, deciphering and referencing them. As in the case of printed works, the correctness of an reference is not obtainable without checking the original. All your solutions, however, contained information about the collection, the name of the codex, sheet number and side, as well as references to secondary sources such as catalogs, scholarly publications, fable editions, facsimiles, transliterations and digital libraries. So they comply with the Leonardologist’s Reference Style.