https://www.packtpub.com/books/info/authors/heiko-horn

Apple Certified System Administrator 10.5
Apple Certified Technical Coordinator 10.8
Cisco Certified Network Associate: Routing and Switching
Google Apps Certified Administrator
Microsoft Certified Professional
Microsoft Certified Solutions Expert: Server Infrastructure, Messaging, Cloud Platform and Infrastructure, Productivity
Microsoft Certified Solutions Associate: Windows Server 2012, SQL Server 2012/2014, Office 365
Microsoft Technology Associate: IT Infrastructure, Database