Pairoaj Tiranathanagul. (1968) Counter studies of cosmic ray nucleons by neutron monitor at latitude 13° 46'(N). Chulalongkorn University:ม.ป.ท.Pairoaj Tiranathanagul. 1968. Counter studies of cosmic ray nucleons by neutron monitor at latitude 13° 46'(N). ม.ป.ท.:Chulalongkorn University;Pairoaj Tiranathanagul. Counter studies of cosmic ray nucleons by neutron monitor at latitude 13° 46'(N). ม.ป.ท.:Chulalongkorn University, 1968. Print.