On the Infinitesimal approach to learning/teaching calculus, popular books being recommended are like Calculus Made Easy, Calculus for the Practical Man. Non-standard Calculus books utilizing the hyper-reals like - Keisler, Bell or Henle are also recommended.
What I have been looking for are books or textbooks (any language), which were used to teach courses or were popular that used the infinitesimal approach before the entire curriculum shifted fully towards formal/rigorous Limit centered & epsilon-delta methods. [e.g., on the lines of Klein, the evolution of teaching Infinitesimal Calculus - dating back to Johann Bernoulli/ L'Hospital, and a little modern Markoff's or Nolund's Differenzenrechnung etc., - have not read these, just heard them referenced.]
I have been looking for such classic books or textbooks (out of curiosity) that might be available online, (most probably not available in print anymore.) or any modern books that still take that approach.
Thanks in advance.