Hunters Hunted pg. 64
Vampire Players Guide (1993) pg. 30
Book of Shadows pg. 38 has it as a Merit.
Ascensions Right Hand pg. 109 says each dot of True Faith is a die of countermagick.
Quick & the Dead pg. 65
The Inquisition pg. 63 has most complete system.
Mage Revised Edition pg. 298 has it as a Merit.