Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Flow diagram: update of the source guidelines used for the original version
Abbreviations of reasons for exclusion:
OS: Other subject
OP: Other type of publication
OW: Withdrawn
OL: Language other than English or German
OT: Other time of publication or search (no update/older than 5 years)
