PlastigaugeUSA.com)
http://www.plastigaugeusa.com/

How Plastigauge Works
http://www.plastigaugeusa.com/how.html
http://www.jensenhealey.com/tech/plastigauge/how-to-use-plastigauge.html

Using Plastigauge to check clearances
http://guy-croft.com/viewtopic.php?f=3&t=950&p=4964&hilit=plastigauge#p4964

Fundamentals of Measuring bearing clearences
http://www.fordmuscle.com/fundamentals/plastiguage/

How to use plastigage to measure clearances
http://www.ehow.com/how_2142943_use-plastigage-measure-clearances.html

Plastigaging bearing clearances
http://mechdb.com/index.php/Plastigaging_bearing_clearances

Inspecting and Measuring the Crankshaft,
Main Bearings, and Saddle Bores
http://webtools.delmarlearning.com/sample_chapters/had73024_139_ch139.pdf