Some development of the model could have been left to the references and didn't add much to their contribution (e.g. Taylor approximation to a Lie model) .	['con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'con', 'non', 'non', 'non', 'non', 'non', 'non', 'non', 'non', 'non', 'non']	paper quality