A methodological approach to strategic petroleum reserveshttp://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VC4-48NC08N-5V&_user=2018000&_coverDate=12%2F31%2F1982&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_searchStrId=1718847120&_rerunOrigin=google&_acct=C000050602&_version=1&_urlVersion=0&_userid=2018000&md5=e158e770cdb0b58e0ceab03b143dadbf&searchtype=a