PZM Mics: How Do They Work? by Sweetwater - YouTube
PZM!: The inexpensive mic that can do a lot! | Tape Op Magazine | Longform candid interviews with music producers and audio engineers covering mixing, mastering, recording and music production.
Crown PZM-185 Condenser Boundary Microphone – MSU Surplus Store
Crown Models PZM-30GPB, PZM-30D
Crown PZM-6LP Boundary Effect Pressure Zone Microphone & PX-18 Power S – ProStudioConnection LLC