D.F. Ryan
Likens, Gene E., Charles T. Driscoll, Donald C. Buso, T.G. Siccama, Chris E. Johnson, Gary M. Lovett, Timothy J. Fahey, et al. 1998. “The Biogeochemistry Of Calcium At Hubbard Brook”. Biogeochemistry 41: 89-173.
Likens, Gene E., Charles T. Driscoll, Donald C. Buso, T.G. Siccama, Chris E. Johnson, Gary M. Lovett, D.F. Ryan, Timothy J. Fahey, and W.A. Reiners. 1994. “The Biogeochemistry Of Potassium At Hubbard Brook”. Biogeochemistry 25: 61-125.