Subject
- Parkinson, Francis, Jr.1
- Pesticides1
- Pesticides industry1
- Photographers8
- Photography8
- Photography--Equipment and supplies6
- Photography--Printing processes1
- Photography--Retouching1
- Physicists1
- Pillsbury Company1
- Pilot plants1
- Plants6
- Plastics55
- Plastics in packaging5
- Plastics industry and trade50
- Plastics--Extrusion12
- Plastics--Testing2
- Pletcher, D.E.1
- Polymers5
- Polystyrene19