1. Juhász, A. Small cancellation theory with unified small cancellation condition. J. London. Math. Soc. 2 (40):57–80 (1989).
2. Juhász, A. Solution of the membership problem of Magnus subgroups of onerelator free products with small cancellation condition. In: Algebra and Geometry in Geneva and Barcelona, “Asymptotic and Probabilistic Methods in Geometric Group Theory”, Geneva, June 2005 and “Barcelona Group Theory Conference”, Barcelona, July 2005, 169–195, Birkhäuser (2007).
3. Juhász, A. A Freiheitssatz for Whitehead graphs of one-relator groups with small cancellation. Communications in Algebra 37:8, 2714–2741 (2009).
4. Johnson, D.L. Topics in the Theory of Group Presentations. LMSLNS, Cambridge University Press, Cambridge. 42 (1980).
5. Lyndon, R.C., Schupp, P.E. Combinatorial Group Theory, Springer-Verlag, Berlin-Heidelberg-New York, (1977).