@article{Hillen1979,
  author    = {Hillen, Walter},
  title     = {Evidence for planar events in e+e\&\#8722; annihilation at high energies. TASSO Collaboration},
  series = {Physics Letters B. 86 (1979), H. 2},
  journal   = {Physics Letters B. 86 (1979), H. 2},
  isbn      = {0370-2693},
  pages     = {243 -- 249},
  year      = {1979},
  language  = {en}
}
@article{Hillen1979,
  author    = {Hillen, Walter},
  title     = {Energy scan for narrow states in e+e\&\#8722; annihilation at C.M. energies between 29.90 and 31.46 GeV. TASSO Collaboration},
  series = {Physics Letters B. 88 (1979), H. 1-2},
  journal   = {Physics Letters B. 88 (1979), H. 1-2},
  isbn      = {0370-2693},
  pages     = {199 -- 202},
  year      = {1979},
  language  = {en}
}
@article{ZastrowPanagiotopoulos1979,
  author    = {Zastrow, Udo and Panagiotopoulos, P. D.},
  title     = {An integral "Equation" approach to the unilateral contact problem},
  series = {ZAMM - Zeitschrift f{\"u}r angewandte Mathematik und Mechanik. 59 (1979), H. 8},
  journal   = {ZAMM - Zeitschrift f{\"u}r angewandte Mathematik und Mechanik. 59 (1979), H. 8},
  isbn      = {1521-4001},
  pages     = {392 -- 393},
  year      = {1979},
  language  = {en}
}