@article{10_2140_agt_2009_9_2191,
     author = {Janzen, David and Wise, Daniel~T},
     title = {A smallest irreducible lattice in the product of trees},
     journal = {Algebraic and Geometric Topology},
     pages = {2191--2201},
     year = {2009},
     volume = {9},
     number = {4},
     doi = {10.2140/agt.2009.9.2191},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2009.9.2191/}
}