To cite the alr4 package in publications use:

Weisberg S (2014). Applied Linear Regression, 4th Edition. Wiley. Data sets discussed in this book, http://z.umn.edu/alr4ed.

Corresponding BibTeX entry:

  @Book{,
    title = {Applied Linear Regression, 4th Edition},
    publisher = {Wiley},
    author = {Sanford Weisberg},
    year = {2014},
    note = {Data sets discussed in this book},
    url = {http://z.umn.edu/alr4ed},
  }