@article{11552,
  author = {Wesley Brittin and W. Chappell},
  title = {Functional Methods in Statistical Mechanics. I. Classical Theory},
  year = {1969},
  journal = {Journal of Mathematical Physics},
  volume = {10},
  pages = {661},
  month = {Jan-01-1969},
  issn = {00222488},
  doi = {10.1063/1.1664892},
}