Gazulli attended schools in Shkodër and Ragusa, and in 1425 he graduated from University of Padua. In 1432 he traveled to the Hungarian royal court where he attempted to persuade Sigismund I in supporting Albanian resistance against the Ottoman Empire. He broke his mission off in 1433, when he was appealed to be a professor of mathematics and astronomy at the University of Padua. Years later he was acting as a diplomat with the Italian principalities' courts, representing the interests of Skanderbeg and of the League of Lezhë.
His lasting mathematical and astronomical works were written in Latin. He was renowned for his considerable knowledge, in Italy and in Hungary, as well. His brother, Pal Gazulli (1405–1470) was the diplomat of Skanderbeg and of the League of Lezhë in Ragusa. He had a second brother named Andrea Gazulli, also mentioned as prominent.
|a.||^ Also known in Albanian as Gjon Gjin Gazulli, or even Gjin Gazulli. In Croatian he is as Ivan Gazulić, Ivan Gazul and Ivan Gazoli > In Serbian he is known as Jovan Gazulić.|
|b.||^ Not to be confused with Dom Gjon Gazulli, an Albanian Catholic Cleric, executed by Ahmet Zogu's regime in 1927.|
- Jacques 1995, pp. 188–189
- Proleksis enciklopedija LZMK Gazulli (Gazulić), Gjin (Ivan, Joannes) Refresged: February 20, 2014. Accessed June 9, 2016 (in Croatian)
- Frashëri 2002, p. 170
- (in Croatian) Prilozi za istraživanje hrvatske filozofske baštine, Vol.3. No.5-6 Prosinac 1977. Vladimir Bazala: Nekoliko hrvatskih prirodoslovaca - filozofa, p. 182-183 (accessed June 9, 2016)
- (in Italian) SRAZ LVIII, 2013. Smiljka Malinar: Tideo Acciarini, un magister scholarum d’Oltreadriatico nella Dalmazia umanistica, p. 80
- (in Croatian) RADOVI - Zavod za hrvatsku povijest, vol. 44, 2012 Tomislav Matić: Renesansa u državi Matijaša Korvina u suvremenoj historiografiji, p. 238 (accessed June 9, 2016) Quote: "... dominikancu i astrologu Gjinu Gazulliju (Johannes Gazulus, odnosno Ivan Gazulić u hrvatskoj tradiciji"
- Gjergj Erebara, Akuza: Ahmet Zogu vari priftin intelektual më 1927 [Gjergj Erebara, Accusation: Ahmet Zogu executed by hanging the intellectual priest in 1927] (in Albanian), Drini Magazine, 2012-03-12, archived from the original on 2013-10-08, retrieved 2013-10-07
- Frashëri, Kristo (2002), Gjergj Kastrioti Skënderbeu: jeta dhe vepra, 1405–1468 (in Albanian), Botimet Toena, ISBN 99927-1-627-4
- Jacques, Edwin E. (1995), The Albanians: an ethnic history from prehistoric times to the present, McFarland, ISBN 978-0-89950-932-7
- Schmitt, Oliver Jens (2001), Das venezianische Albanien (1392-1479), Oldenbourg Wissenschaftsverlag, ISBN 978-3-486-56569-0