found: Milwid, A.Sinfonia concertante, per oboe ed orchestra, c1952.
found: Szymanowski, K. Concerto no. 1 for violin and orchestra, op. 35 [SR] c1975:container (conductor: Jan Krenz)
found: Koncert fortepianowy a-moll op. 17, 1983?:label (J. Krenz)
found: New Grove(Krenz, Jan; b. July 14, 1926, Włocławek; Polish conductor and composer)
found: MGG(Krenc, Jan)
found: Wikipedia, October 6, 2020(Jan Krenz; born July 14, 1926, Włocławek, Second Polish Republic; died September 15, 2020; Polish composer and orchestra conductor)
found: MGG online, October 12, 2020(Krenz, Jan; born July 14, 1926, Włocławek; died September 15, 2020, Katowice; composer and conductor)