Paul L. V. Héroult, « Obituaries - Herman Frasch, », Industrial & Engineering Chemistry, vol. 6, no 6, , p. 505–507 (DOI10.1021/ie50066a024)
Cf. Samuel H. Lebowitz, « A demonstration working model of the Frasch Process for mining sulfur », J. Chem. Educ., vol. 8, no 8, , p. 1630 (DOI10.1021/ed008p1630, Bibcode1931JChEd...8.1630L)
harvard.edu
ui.adsabs.harvard.edu
Cf. Samuel H. Lebowitz, « A demonstration working model of the Frasch Process for mining sulfur », J. Chem. Educ., vol. 8, no 8, , p. 1630 (DOI10.1021/ed008p1630, Bibcode1931JChEd...8.1630L)
D’après Diana J. Kleiner, « Sulfur industry », sur Handbook of Texas Online (consulté le ).
usgs.gov
pubs.usgs.gov
Joyce A. Ober, Materials flow of sulfur, US Geological Survey (USGS) Open-File Report 02-298, U.S. Dept. of the Interior, USGS, (lire en ligne), p. 12–13