Inter Gravissimas Bill Spencer's (in αγγλική) translation of the Inter Gravissimas, 1999, revised 2002, based on Rodolphe Audette's transcription of the (in Latin) text. Also includes Rodolphe Audette's translation into (in γαλλική).
"Inter gravissimas" in Christoph Clavius, Romani calendarii a Gregorio XIII. P. M. restituti explicatio, 1603). (in Latin) The bull begins on page 53, counting from the front cover. The title page is page 5.
"Inter gravissimas" in Christoph Clavius, Romani calendarii a Gregorio XIII. P. M. restituti explicatio, 1603. (in Latin) The bull begins on page 53, counting from the front cover. The title page is page 5.
nd.edu
mathematics.library.nd.edu
Opera Mathematica of Christoph Clavius(in Latin) Go to Page, Go To Specific Page, Work: Roman Calendar of Gregory XIII, Page: Calendar – Page 13. The fifth volume contains his works on the Gregorian calendar.