↑ J. M. Steele, University of Toronto, (review online from Canadian Association of Physicists) Archived 1 เมษายน 2010 ที่ เวย์แบ็กแมชชีน of N. Guicciardini's "Reading the Principia: The Debate on Newton's Mathematical Methods for Natural Philosophy from 1687 to 1736" (Cambridge UP, 1999), a book which also states (summary before title page) that the "Principia" "is considered one of the masterpieces in the history of science".
↑ The content of infinitesimal calculus in the "Principia" was recognized both in Newton's lifetime and later, among others by the Marquis de l'Hospital, whose 1696 book "Analyse des infiniment petits" (Infinitesimal analysis) stated in its preface, about the "Principia", that "nearly all of it is of this calculus" ("lequel est presque tout de ce calcul"). See also D. T. Whiteside (1970), "The mathematical principles underlying Newton's Principia Mathematica", Journal for the History of Astronomy, vol. 1 (1970), 116–138, especially at p. 120.
