Möbius transformations and isoclinal sequences of spheres. (Short Communication). J.B. Wilker — 1985 Aequationes mathematicae
Möbius transformations and isoclinal sequences of spheres. J.B. Wilker — 1986 Aequationes mathematicae
A case of the 3-dimensional problem of Appollonius. J.B. Wilker; M. Paluszny — 1991 Aequationes mathematicae
Further thoughts on a focusing property of the ellipse. Wilker, J.B. — 1995 Bulletin of the Belgian Mathematical Society - Simon Stevin
The View-Obstruction Problem for Spheres in ...5. J.B. Wilker; V.C. Dumir; R.J. Hans-Gill — 1996 Monatshefte für Mathematik