Sentence:  Several germanium resistors have been thermally cycled from 300 to 4.2 * * f and their resistances have been found to be reproducible within 1 3 <WSD>millidegree</WSD> when temperatures were derived from a vapor pressure thermometer whose tubing is jacketed through most of the liquid helium . 
Meaning of the word marked with <WSD> tags:  a unit of temperature equal to one-thousandth of a degree