13. Coll 30/87(1) 'Qatar: Oil Concession.' Date: 1933/1935 Language: English Geographic region: Qatar
14. Coll 30/87(2) Part I 'Qatar: Oil Concession.' Date: 1935/1944 Language: English Geographic region: Qatar
15. Coll 30/87(2) Part II 'Qatar: Oil Concession - P.C.L.'s Operations.' Date: 1945/1948 Language: English Geographic region: QatarBahrain