@article{10_4171_ggd_173,
     author = {Christopher F. Novak},
     title = {Interval exchanges that do not occur in free groups},
     journal = {Groups, geometry, and dynamics},
     pages = {755--763},
     year = {2012},
     volume = {6},
     number = {4},
     doi = {10.4171/ggd/173},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/173/}
}