Deletion of Masreliez's theorem

Comment: Searching Google scholar for this exact phrase finds multiple publications by disjoint sets of authors, none of them Masreliez himself, that all appear to be about this topic: "A representation of the posterior mean for a location model", NG Polson, Biometrika 1991; "Kalman filter with a non-linear non-Gaussian observation relation", T Cipra & A Rubio, Trabajos de Estadistica 1991; "Non-Gaussian State-Space Modeling of Nonstationary Time Series: Comment: Robustness, Computation, and Non-Euclidean Models" RD Martin & AE Raftery, JASA 1987 (a top author in a top journal); etc. I think that's enough for the low bar of 
Stance: keep
Cited policy: Wikipedia:Notability (WP:GNG)