https://aapt.scitation.org/doi/full/10.1119/1.2341882 - sorry, just learnt this is not an open access article
https://aapt.scitation.org/doi/full/10.1119/1.5126818 (Oberth Effect)
There is no such thing as "not open access article".
https://sci-hub.se/https://doi.org/10.1119/1.2341882
(With a big thank you to Alexandra Elbakyan.)
https://aapt.scitation.org/doi/full/10.1119/1.2341882 - sorry, just learnt this is not an open access article
https://aapt.scitation.org/doi/full/10.1119/1.5126818 (Oberth Effect)