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In the early 1970s , when the `` world food crisis '' was a major worry , Phillips Petroleum Co. , like several other big companies , began developing `` single - cell protein , '' edible protein made by microbes feeding on non-edible materials .
 the early 1970s, Phillips Petroleum Co.
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: date, organization, person, geographical social political, national religious political, facility, cardinal, location, work of art, law, event, product, ordinal, percent, time, quantity, money, language 
Text: {0} 
Answer:
 the early 1970s, Phillips Petroleum Co.