| Reference | {Deposit:: BRITISH SULPHUR CORP. LTD., 1980: WORLD SURVEY OF PHOSPHATE DEPOSITS, 4TH ED., LONDON}{Deposit:: ANONYM, 1980: MEXICO-PHOSPHATE ROCK PRODUCER OF THE FUTURE. PHOSPHORUS & POTASSIUM, NO.109, SEPT./OCT. 1980, P.20-24}{Deposit:: CLARKE, G. 1980: MEXICAN PHOSPHATE..., INDUSTRIAL MINERALS, NO.152, MAY 1980, P.79-91, LONDON}{Production:: INDUSTRIAL MINERALS, NO.152, MAY 1980, LONDON} |