http:// qtagg.com/references.html
http:// www.westinghousenuclear.com/Portals/0/operating%20plant%20services/automation/protection%20systems/NA-0008%20Common%20Q%20Post-accident%20Monitoring.pdf
https:// books.google.com/books?id=qSpkAAAAcAAJ&pg=PP1&lpg=PP1&dq=common+Q+references&source=bl&ots=ahgWuXw6hI&sig=B7T1VB9rSCzYqf7ujyOZkmBtqwg&hl=en&sa=X&ved=2ahUKEwjynMSksc7aAhVyxFkKHdbTChcQ6AEwAnoECAkQAQ#v=onepage&q=common%20Q%20references&f=false
https:// books.google.com/books?id=xWKjH787JEwC&pg=PA348&lpg=PA348&dq=common+Q+references&source=bl&ots=DMEdzZJrC_&sig=btQ2kHTZ-hsEFU-9LtUzwAUZsIs&hl=en&sa=X&ved=2ahUKEwjynMSksc7aAhVyxFkKHdbTChcQ6AEwCXoECAIQAQ#v=onepage&q=common%20Q%20references&f=false