Drawing of the proposed U.S. Navy New-Design Battle Group Destroyer (DDGX) and Open Ocean Destroyer (DDGY).
Congress of the United States, Congressional Budget Office
Congress of the United States, Congressional Budget Office: <i>Naval Surface Combatants in the 1990s: Prospects and Possibilities. A CBO study.</i> U.S. Government Prininting Office, Washington D.C. (USA), April 1981, p. 45.<a rel="nofollow" class="external autonumber" href="https://www.cbo.gov/sites/default/files/97th-congress-1981-1982/reports/doc15-entire_0.pdf">[1]</a>