Kandeel, A. A., J. A. Younis, and A. M. Zaher,  "Significance of popliteal lymph nodes visualization during radionuclide lymphoscintigraphy for lower limb lymphedema",  http://www.ncbi.nlm.nih.gov/pubmed/24250020, vol. 28, issue 3, pp. 134-137, 2013.