@article{223265,
      recid = {223265},
      author = {Lamon, Susan J.,},
      title = {Teaching fractions and ratios for understanding :  essential content knowledge and instructional strategies  for teachers /},
      publisher = {Erlbaum,},
      address = {Mahwah, N.J. :},
      pages = {xiv, 261 p. :},
      year = {1999},
      url = {http://library.usi.edu/record/223265},
}