Bibtex of Permutation / Arrangements

@article{Johnson1963, 
     author = "Johnson, Selmer M.", 
     doi = "10.1090/S0025-5718-1963-0159764-2", 
     issn = "0025-5718", 
     journal = "Mathematics of Computation", 
     link = "http://www.ams.org/mcom/1963-17-083/S0025-5718-1963-0159764-2/", 
     month = "sep", 
     number = "83", 
     pages = "282--282", 
     title = "Generation of permutations by adjacent transposition", 
     uri = "http://www.ams.org/mcom/1963-17-083/S0025-5718-1963-0159764-2/", 
     volume = "17", 
     year = "1963", 
}

@article{Wells1961, 
     author = "Wells, Mark B.", 
     doi = "10.1090/S0025-5718-1963-0159764-2", 
     journal = "Mathematics of Computation", 
     link = "http://www.ams.org/journals/mcom/1961-15-074/S0025-5718-1961-0127507-2/home.html", 
     number = "74", 
     pages = "192--195", 
     title = "Generation of permutations by transposition", 
     uri = "http://www.ams.org/journals/mcom/1961-15-074/S0025-5718-1961-0127507-2/home.html", 
     volume = "15", 
     year = "1961", 
}