This standard applies to ground feldspathic and quartz-feldspathic materials and specifies a method for determining granulosity
GOST 20545-1975 Referenced Document
GOST 22871-1977 Ground feldsparic and quartzfeldsparic materials. Rules of reception. Methods of sampling and sample preparation for testing*, 1977-04-19 Update
GOST 25336-1982 Laboratory glassware and equipment. Basic parameters and dimensions*, 1982-04-19 Update