Application of Sturm's theorem to marginal stable circular orbits of a test body in spherically symmetric and static spacetimesToshiaki Ono, Tomohito Suzuki, Naomasa Fushimi, Kei Yamada and Hideki AsadaEPL, 111 3 (2015) 30008DOI: https://doi.org/10.1209/0295-5075/111/30008