Resumen: Generalized restricted three body problems consist of adding some extra hypotheses to the Restricted three body problem (RTBP) in order to have a new problem, not very different of the original RTBP. However, not any additional hypothesis is allowed; it must satisfy the laws of Physics. Among the several generalizations found in literature, we prove that at least there are two hypotheses that cannot be used, namely: 1) Perturbation in Coriolis and/or centrifugal forces, and 2) primaries are spheroids moving on elliptical orbits. Idioma: Inglés DOI: 10.1007/s10509-024-04286-7 Año: 2024 Publicado en: ASTROPHYSICS AND SPACE SCIENCE 369, 22 (2024), 2-7 ISSN: 0004-640X Financiación: info:eu-repo/grantAgreement/ES/DGA/E24-23R Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2020-117066GB-I00 Tipo y forma: Artículo (Versión definitiva) Área (Departamento): Área Matemática Aplicada (Dpto. Matemática Aplicada)