1) Phenylpropanolamine 2) Pixel processing accelerator 
[complexity] PPA contains PPAD as a subclass. This is because the corresponding problem that defines PPAD, known as END OF THE LINE, can be reduced (in a straightforward way) to the above search for an additional odd-degree vertex (essentially, just by ignoring the directions of the edges in END OF THE LINE). There is an un-oriented version...
See U.S. Department of Agriculture.
Planning, Preparation and Assessment
Pre-School Playgroups Association
Pennsylvania Pharmacists Association
Prescription Pricing Authority
Pay-Per-Action - Affiliate commissions where a set amount is paid for generating a specific action, such as taking a free trial or subscribing to an ezine. PPL, PPC and PPS are usually considered as PPA.
Pay and Personnel Agency.
Pixel Processing Accelerator
The Power Purchase Agreement (PPA) is a contract between the generator and the supplier that outlines how much generators will be paid for any power they generate that is not used locally but exported to the national grid.
Periodical Publishers Association. Industry body representing UK magazine publishers.
See: provisional patent application
): An organisation representing British magazine publishers.
Preferred Provider Arrangement
Peri-papillary atrophy
Planning, Preparation and Assessment time.
Pollution Prevention Act.
phenylpropanolamine.