↑ Vivian Shaw Groza, Susanne M. Shelley (1972), «Precalculus mathematics», New York: Holt, Rinehart, Winston, с. 182, ISBN 978-0-03-077670-0, <https://books.google.com/?id=yM_lSq1eJv8C&pg=PA182&dq=%22arithmetica+integra%22+logarithm&q=stifel>