A. Altavilla: Some properties for quaternionic slice-regular functions on domains without real points Complex Variables and Elliptic Equations (Published) Vol. 60, N. 1, p. 59--77, 2015 A. Altavilla, L. Nicolodi: On the volume of the Sp(n)Sp(1) shadow of a compact set C. R. Math. Acad. Sci. Paris Vol. 354, N. 3, p. 307-311, 2016 A. Altavilla, C. Bisi: Log-biharmonicity and a Jensen formula in the space of quaternions Annales Academię Scientiarum Fennicę-Mathematica (in press) Vol. 44, N. 2, p. 35, 2017 A. Altavilla: Twistor interpretation of slice regular functions Journal of Geometry and Physics (Published) Vol. 123, p. 184--208, 2018 A. Altavilla, E. Ballico: Twistor lines on algebraic surfaces Annals of Global Analysis and Geometry (in press) 2018 A. Altavilla: On the real differential of a slice regular function Advances in Geometry Vol. 18, N. 1, p. 5--26, 2018 A. Altavilla, C. de Fabritiis: S-regular functions which preserve a complex slice Annali di Matematica Pura e Applicata (Research Paper) Vol. 197, N. 4, p. 1269--1294, 2018 A. Altavilla, G. Sarfatti: Slice-Polynomial Functions and Twistor Geometry of Ruled Surfaces in $\mathbb{CP}^3$ Mathematische Zeitschrift Vol. 291, 2019 A. Altavilla, E. Ballico: Three Topological Results on the Twistor Discriminant Locus in the 4-Sphere Milan Journal of Mathematics (published) p. 16, 2019 A. Altavilla, C. de Fabritiis: $*$-exponential of slice-regular functions Proceedings of the American Mathematical Society (published) Vol. 147, p. 1173--1188, 2019 A. Altavilla, E. Ballico: Algebraic surfaces with infinitely many twistor lines (preprint) 2019 A. Altavilla, S. Mongodi: The $*$-exponential as a covering map (preprint) 2023