"Short description: In Russian. Rosenberg, Lazar Davidovich. Sound Focusing Systems. Moscow: Publishing House and Second Type. Publishing House of Akad. Sciences of the USSR in Moscow; Leningrad, 1949. You are welcome to reach out to us for a detailed description of the copies currently available. Delivery of this book may take longer than usual including extended processing and pre-shipping time, no expedited shipping is available. Please advise us if you have a set date or a deadline to receive your order.SKU6005712"