Returns a list of models which have the minimum target field value
        for a given field name (AIC or BMDL).

def _get_recommended_models(models, fld_name):
        """
        Returns a list of models which have the minimum target field value
        for a given field name (AIC or BMDL).
        """
        target_value = min([model.output[fld_name] for model in models])
        return [model for model in models if model.output[fld_name] == target_value]