изоорстсни М. Котов В. Берман Э. Г. чпсв Ю. Я. Григ рьев
Б. С. ар
Л. Л. Скочипского Институт горного ле
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filedfiledCritical
Priority to SU1474500ApriorityCriticalpatent/SU394271A1/ru
Application grantedgrantedCritical
Publication of SU394271A1publicationCriticalpatent/SU394271A1/ru