Theoretical elements of electrical engineering 2026-02-16T08:04:39+03:00 DEBUG: VuFind\ILS\Driver\Folio: Token taken from global cache: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiO... - Steinmetz, Charles Proteus, 1865-1923 (McGraw-Hill, 1915)