@article{ Higman59,
  author =           {Higman, G.},
  title =            {Some remarks on varieties of groups},
  journal =          {Quart. J. Math. Oxford},
  volume =           {2},
  number =           {10},
  year =             {1959},
  pages =            {165{\textendash}178},
  printedkey =       {Hig59}
}
@article{ LS90,
  author =           {Leedham-Green, C. R. and Soicher, L. H.},
  title =            {Collection from the left and other strategies},
  journal =          {J. Symbolic Comput.},
  volume =           {9},
  number =           {5{\textendash}6},
  year =             {1990},
  pages =            {665{\textendash}675},
  printedkey =       {LS90}
}
@article{ NewmanNickel94,
  author =           {Newman, M. F. and Nickel, W.},
  title =            {Engel elements in groups},
  journal =          {J. Pure Appl. Algebra},
  volume =           {96},
  year =             {1994},
  pages =            {39{\textendash}45},
  printedkey =       {NN94}
}
@inproceedings{ Nickel96,
  author =           {Nickel, W.},
  booktitle =        {Geometric  and  Computational Perspectives on Infinite
                      Groups},
  title =            {Computing  Nilpotent  Quotients  of Finitely Presented
                      Groups},
  series =           {Dimacs  Series in Discrete Mathematics and Theoretical
                      Computer Science},
  volume =           {25},
  year =             {1996},
  pages =            {175{\textendash}191},
  printedkey =       {Nic96}
}
@book{ Sims94,
  author =           {Sims, C. C.},
  title =            {Computation with Finitely Presented Groups},
  publisher =        {Cambridge University Press},
  year =             {1994},
  printedkey =       {Sim94}
}
@article{ VL90a,
  author =           {Vaughan-Lee, M. R.},
  title =            {Collection from the Left},
  journal =          {J. Symbolic Comput.},
  publisher =        {Academic Press},
  volume =           {9},
  year =             {1990},
  pages =            {725{\textendash}733},
  printedkey =       {Vau90}
}
@misc{ polycyclic,
  author =           {Eick, B. and Nickel, W.},
  title =            {Polycyclic,  Algorithms  for  working  with polycyclic
                      groups},
  year =             {2002},
  note =             {GAP package},
  howpublished =     {\href     {https://gap-packages.github.io/polycyclic/}
                      {\texttt{https://gap-packages.github.io/}\discretionary
                      {}{}{}\texttt{polycyclic/}}},
  printedkey =       {EN02}
}
@manual{ GNUMP,
  title =            {GNU MP},
  address =          {\href                            {https://gmplib.org/}
                      {\texttt{https://gmplib.org/}}},
  key =              {GMP}
}
@manual{ GAP4,
  title =            {{GAP}  --  {G}roups,  {A}lgorithms, and {P}rogramming,
                      Version 4.11.1},
  organization =     {The GAP Group},
  year =             {2021},
  note =             {\href                     {https://www.gap-system.org}
                      {\texttt{https://www.gap-system.org}}},
  key =              {GAP},
  keywords =         {groups; *; gap; manual}
}