The Structure of C1 Spline Spaces on Freudenthal Partitions. - Gero Hecklin; Günther Nürnberger; Frank Zeilfelder (SIAM J. Math. Anal., 2006)

A local Lagrange interpolation method based on C1 cubic splines on Freudenthal partitions. - Gero Hecklin; Günther Nürnberger; Larry L. Schumaker; Frank Zeilfelder (Math. Comput., 2008)

Local lagrange interpolation with cubic C1 splines on tetrahedral partitions. - Gero Hecklin; Günther Nürnberger; Larry L. Schumaker; Frank Zeilfelder (J. Approx. Theory, 2009)