Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Shinichi HANAYAMA,Introduction of 4th IMO GHG Study 2020 : Trends of GHG emissions and Carbon Intensity from 2008 to 2012,ClassNK technical journal,,Tokyo : Nippon Kaiji Kyokai Research Institute,2020-12,2020,1,1-12,https://cir.nii.ac.jp/crid/1523106606081726464,