@article{RSMUP_2017__138__39_0,
     author = {Bubboloni, Daniela},
     title = {Graph homomorphisms and components of quotient graphs},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {39--60},
     publisher = {European Mathematical Society Publishing House},
     address = {Zuerich, Switzerland},
     volume = {138},
     year = {2017},
     doi = {10.4171/RSMUP/138-2},
     mrnumber = {3743244},
     zbl = {1387.05164},
     url = {http://www.numdam.org/articles/10.4171/RSMUP/138-2/}
}