FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH "ESA ." The Oxford Dictionary of Abbreviations. . Encyclopedia.com. (April 16, 2024). https://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/esa

FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH "ESA ." The Oxford Dictionary of Abbreviations. . Retrieved April 16, 2024 from Encyclopedia.com: https://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/esa

AILSA ALLABY and MICHAEL ALLABY "ESA ." A Dictionary of Earth Sciences. . Encyclopedia.com. (April 16, 2024). https://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/esa

AILSA ALLABY and MICHAEL ALLABY "ESA ." A Dictionary of Earth Sciences. . Retrieved April 16, 2024 from Encyclopedia.com: https://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/esa