@article{42801,
  abstract     = {{We exhibit a practical algorithm for solving the constructive membership problem for discrete free subgroups of rank 2 in PSL₂(R) or SL₂(R). This algorithm, together with methods for checking whether a two-generator subgroup of PSL₂(R) or SL₂(R) is discrete and free, have been implemented in Magma for groups defined over real algebraic number fields.}},
  author       = {{Kirschmer, Markus and LEEDHAM-GREEN, CHARLES}},
  issn         = {{0017-0895}},
  journal      = {{Glasgow Mathematical Journal}},
  keywords     = {{General Mathematics}},
  number       = {{1}},
  pages        = {{173--180}},
  publisher    = {{Cambridge University Press (CUP)}},
  title        = {{{Computing with subgroups of the modular group }}},
  doi          = {{10.1017/s0017089514000202}},
  volume       = {{57}},
  year         = {{2014}},
}

@article{64685,
  author       = {{Glöckner, Helge}},
  issn         = {{0017-0895}},
  journal      = {{Glasgow Mathematical Journal}},
  keywords     = {{26E15, 26E20, 26E30, 46A16, 46S10}},
  number       = {{2}},
  pages        = {{271–288}},
  title        = {{{Ultrametric and non-locally convex analogues of the general curve Lemma of convenient differential calculus}}},
  doi          = {{10.1017/S0017089508004199}},
  volume       = {{50}},
  year         = {{2008}},
}

@article{64701,
  author       = {{Glöckner, Helge}},
  issn         = {{0017-0895}},
  journal      = {{Glasgow Mathematical Journal}},
  keywords     = {{22D05, 22D40, 22D45}},
  number       = {{2}},
  pages        = {{329–333}},
  title        = {{{Contraction groups for tidy automorphisms of totally disconnected groups}}},
  doi          = {{10.1017/S0017089505002557}},
  volume       = {{47}},
  year         = {{2005}},
}

@article{64718,
  author       = {{Glöckner, Helge}},
  issn         = {{0017-0895}},
  journal      = {{Glasgow Mathematical Journal}},
  keywords     = {{22D05, 22E50, 20E26, 14L10}},
  number       = {{2}},
  pages        = {{231–239}},
  title        = {{{Approximation by p-adic Lie groups}}},
  doi          = {{10.1017/S0017089502020049}},
  volume       = {{44}},
  year         = {{2002}},
}