@InCollection{jue:21b,
  author = 	 {K. Birner and B. J\"uttler and A. Mantzaflaris},
  title = 	 {Approximation power of ${C}^1$-smooth isogeometric
                  splines on volumetric two-patch domains},
  booktitle = 	 {Isogeometric Analysis and Applications 2018},
  publisher =    {Springer International Publishing},
  year = 	 {2021},
  editor = 	 {H. van Brummelen and others},
  volume = 	 {133},
  series = 	 {Lecture Notes in Computational Science and Engineering},
  pages = 	 {27-38},
  doi  =         {10.1007/978-3-030-49836-8_2}
}