Pietrzkowski, Z., Phelan, M. J., Keller, R., Shu, C., Argumedo, R., & Reyes-Izquierdo, T. (2014). Short-term efficacy of calcium fructoborate on subjects with knee discomfort: A comparative, double-blind, placebo-controlled clinical study. Dove Medical Press.

Pietrzkowski, Zbigniew, Michael J. Phelan, Robert Keller, Cynthia Shu, Ruby Argumedo, và Tania Reyes-Izquierdo. Short-term Efficacy of Calcium Fructoborate On Subjects With Knee Discomfort: A Comparative, Double-blind, Placebo-controlled Clinical Study. Dove Medical Press, 2014.

Pietrzkowski, Zbigniew, et al. Short-term Efficacy of Calcium Fructoborate On Subjects With Knee Discomfort: A Comparative, Double-blind, Placebo-controlled Clinical Study. Dove Medical Press, 2014.