  
  
  [1XReferences[101X
  
  [[20XAL07[120X]  [16XAssmann, B. and Linton, S.[116X, [17XUsing the Mal'cev correspondence for collection
  in polycyclic groups[117X, [18XJournal of Algebra[118X (2007).
  
  [[20XGeb02[120X]  [16XGebhardt,  V.[116X, [17XEfficient collection in infinite polycyclic groups[117X, [18XJournal
  of Symbolic Computation[118X, [19X34[119X, 3 (2002), 213--228.
  
  [[20XLS90[120X]  [16XLeedham-Green, C. R. and Soicher, L. H.[116X, [17XCollection from the left and other
  strategies[117X, [18XJournal of Symbolic Computation[118X, [19X9[119X (1990), 665 -- 675.
  
  [[20XMal51[120X] [16XMal'cev, A. J.[116X, [17XOn certain classes of infinite soluble groups[117X, [18XMat. Sb.[118X, [19X28[119X
  (1951), 567 -- 588.
  
  [[20XSeg83[120X] [16XSegal, D.[116X, [17XPolycyclic Groups[117X, Cambridge University Press, Cambridge (1983).
  
  [[20XVau90[120X] [16XVaughan-Lee, M.[116X, [17XCollection from the left[117X, [18XJournal of Symbolic Computation[118X,
  [19X9[119X (1990), 725--733.
  
  
  
  [32X
