@article{10_21136_MB_2002_133982,
     author = {Zelinka, Bohdan},
     title = {The 3-path-step operator on trees and unicyclic graphs},
     journal = {Mathematica Bohemica},
     pages = {33--40},
     publisher = {mathdoc},
     volume = {127},
     number = {1},
     year = {2002},
     doi = {10.21136/MB.2002.133982},
     mrnumber = {1895244},
     zbl = {0995.05076},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/MB.2002.133982/}
}