Source list

• Globewire Press Release, BCG Revenue hits $5.4B
• McKinsey & Co homepage, Who we are page
• Forbes, McKinsey & Co. company profille
• Forbes, Bain & Co. company profile
• Wikipedia, Accenture main page
• Wikipedia, Deloitte main page
• Wikipedia, FTI Consulting main page
• Wikipedia, Navigant Consulting main page
• Vault.com, 2016 McKinsey & Co. company profile