- 80/20 PrincipleRichard Koch
- The 80/20 PrincipleRichard Koch
- The 80/20 IndividualRichard Koch
- SimplifyRichard Koch, Greg Lockwood
- El principio 80/20Richard Koch, Montserrat Asensio Fernández
- 80/20 ManagerRichard Koch
- The 80/20 Principle : The Secret of Achieving More with LessRichard Koch
- Principio del 80/20, El (Paidos Empresa)Richard Koch
- Star Principle, TheRichard Koch, Richard Aspel
- Understanding the Mentally Retarded ChildRichard Koch
- Unreasonable Success and How to Achieve ItRichard Koch
- SuperconnectRichard Koch, Greg Lockwood
- Living The 80/20 WayRichard Koch
- The Financial Times Guide to Management and FinanceRichard Koch
- Managing Without ManagementRichard Koch
- Smart StrategyRichard Koch
- The Breakthrough Principle of 16xRichard Koch
- Le principe 8o/20 faire plus avec moinsRichard Koch
- Selecting Shares That PerformRichard Koch
