@other{https://resolver.caltech.edu/CaltechTHESIS:11292012-114339075, title = "A study of the ultrahigh-energy cosmic ray mass composition with the MACRO and EAS-TOP experiments", year = "1993", url = "https://resolver.caltech.edu/CaltechTHESIS:11292012-114339075", id = "record", doi = "10.7907/vp18-zv27" }