S. Taylor, J. H. Lever e R. P. Harvey, Numbers, Types and Compositions of an Unbiased Collection of Cosmic Spherules, in Meteoritics & Planetary Science, vol. 35, n. 4, 2000, pp. 651–666, Bibcode:2000M&PS...35..651T, DOI:10.1111/j.1945-5100.2000.tb01450.x.
S. Taylor, J. H. Lever e R. P. Harvey, Numbers, Types and Compositions of an Unbiased Collection of Cosmic Spherules, in Meteoritics & Planetary Science, vol. 35, n. 4, 2000, pp. 651–666, Bibcode:2000M&PS...35..651T, DOI:10.1111/j.1945-5100.2000.tb01450.x.