Simultaneous diophantine approximation with square-free numbers R. C. Baker; J. Brüder; G. Harman — 1993 Acta Arithmetica
Odd order flag-transitive affine planes of dimension three over their kernel. Baker, R. D.; Culbert, C.; Ebert, G. L.; Mellinger, K. E. — 2003 Advances in Geometry