Elementary differential equations 2026-02-16T08:49:19+03:00 DEBUG: VuFind\ILS\Driver\Folio: Token taken from global cache: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiO... - Rainville, Earl David, 1907-; Bedient, Phillip Edward, 1922-; Bedient, Richard E. (Prentice Hall, 1997)