You can also connect to de.linkedin.com
Linkedin is a social Media website for Professional People.
It does not list German phonenumbers like historic Whitepages
but profiles of individual people.
Connected to Linkedin you can send messages
to people from Germany you found.
Linkedin was founded by Reid Hoffman in California in 2002.
The platform came to the web 2003
2016 Linkedin was acquired by Microsoft.
More on the history of Microsoft
on the Brand Portal VB.com