Your entry Protection of the cultural heritage would be here
Protection of wildlife -- See Wildlife conservation Here are entered works on the protection of wildlife, as a matter of public policy. Works on methods of bringing wildlife populations to desired levels are entered under Wildlife management. --subdivision Conservation under individual animals and groups of animals, e.g. Fishes--Conservation
Protective breathing apparatus -- See Breathing apparatus Here are entered works on equipment that provides the user with a safe supply of air or oxygen in an environment where air is unavailable or unsafe to breathe. Works on equipment used to provide medical care are entered under Respirators (Medical equipment).
Protein complementarity -- See Food combining Here are entered works on the consumption, at the same meal, of foods that complement each other to ensure adequate protein nutrition or that produce the same digestive process to maintain acid-base equilibrium.