That looks like the old German version of the Whitworth pipe thread standard. It's been superseded by:
BS EN 10226-1:2004
BS EN 10226-2:2005
BS EN 10226-3:2005
There's an ISO standard as well - ISO 7-1.
As for purchasing it, you can buy it from BSI amongst others. If you're a member you'll get a discount, or it may be contained within your subscription. A library may also be able to order it in for you without charge from your national library service.