Reference | {Deposit:: BRITISH SULPHUR CORP. LTD., 1980: WORLD SURVEY OF PHOSPHATE DEPOSITS, 4TH ED., LONDON}{Deposit:: ANONYM, 1977: GAFSA REVISITED, PHOSPHORUS & POTASSIUM, NO.90, P.21-24, LONDON}{Production:: BRITISH SULPHUR CORP. LTD., 1980: WORLD SURVEY OF PHOSPHATE DEPOSITS, 4TH ED., P.148, LONDON} |