Authors
Elfer Arenas
Faculty of Natural Sciences, National University San Agustín de Arequipa, Peru
Jorge Martínez
Peruvian Institute of Nuclear Energy, Peru
Mercedes Vilca Guillen
Faculty of Natural Sciences, National University San Agustín de Arequipa, Peru
Alicia Fernandez
Laboratory of Natural Radioactivity, University of Cantabria, Spain
Enrique Fernandez
Laboratory of Natural Radioactivity, University of Cantabria, Spain
