↑ ὕδωρ, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
↑ σφαῖρα, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
↑ “Our Changing Planet: an Introduction to Earth System Science and Global Environmental Change.” Our Changing Planet: an Introduction to Earth System Science and Global Environmental Change, by Fred T. Mackenzie, 2nd ed., Pearson Education, 2011, pp. 88–91.
