Kapovich, Ilya Max Planck Institute for Mathematics, Max Planck Society;
Shpilrain, Vladimir Max Planck Institute for Mathematics, Max Planck Society;
Kapovich, I., Levitt, G., Schupp, P., & Shpilrain, V. (2007). Translation equivalence in free groups. Transactions of the American Mathematical Society, 359(4), 1527-1546. doi:S 0002-9947(06)03929-8.