Citation: Christensen, A. Norlund; Hazell, R. G. (1991). A Comparison of Three Sets of Diffraction Data for Al2Y4O9: X-Ray Synchrotron Powder Data, X-Ray Single Crystal Data from Ag Kalpha Radiation, and Neutron Single Crystal Data from 1.01 A Neutrons. Acta Chemica Scandinavica, 45, pp. 226-230.