引用・参考資料等 https://www.fieldartillery.org/news/army-to-cut-155-mm-artillery-spending-citing-budget-pressurehttps://www.af.mil/About-Us/Fact-Sheets/Display/Article/104572/joint-direct-attack-munition-gbu-313238/https://www.proquest.com/docview/217298323?sourcetype=Trade+Journals
http://www.nicovideo.jp/watch/sm44889396
