Robert H. Perry's 2021 Contract Security Industry White Paper
Security Advisor Newsletter Summer 2021
Robert H. Perry's 2020 Industry Review and 2021 Outlook
Security Letter: 2020 List of Largest Guard Companies in U.S.
Robert H. Perry's 2020 "White Paper" on the State of the Contract Security Industry
U.S. Department of Labor/Bureau of Labor Statistics:
2020 Employment and Wage Data for Security Guards
2020 Occupational Outlook Handbook - Security Guards
Security Letter: 2019 List of Largest Guard Companies in U.S.
2018 Security Magazine List of Top Guarding Companies