Partitions of Vector Spaces Quasi-Subgeometry Partitions Finite Focal-Spreads Generalizing André Spreads The Going Up Construction for Focal-Spreads Subgeometry Partitions Subgeometry and Quasi-Subgeometry Partitions Subgeometries from Focal-Spreads Extended André Subgeometries Kantor's Flag-Transitive Designs Maximal Additive Partial Spreads Subplane Covered Nets and Baer Groups Partial Desarguesian t-Parallelisms Direct Products of Affine Planes Jha-Johnson SL(2, q) × C-Theorem Baer Groups of Nets Ubiquity of Subgeometry Partitions Flocks and Related Geometries Spreads Covered by Pseudo-Reguli Flocks Regulus-Inducing Homology Groups Hyperbolic Fibrations and Partial Flocks j-Planes and Monomial Flocks Derivable Geometries Flocks of α-Cones Parallelisms of Quadric Sets Sharply k-Transitive Sets Transversals to Derivable Nets Partially Flag-Transitive Affine Planes Special Topics on Parallelisms Constructions of Parallelisms Regular Parallelisms Beutelspacher's Construction of Line Parallelisms Johnson Partial Parallelisms Parallelism-Inducing Groups Parallelism-Inducing Groups for Pappian Spreads Linear and Nearfield Parallelism-Inducing Groups General Parallelism-Inducing Groups Coset Switching Finite E-Switching Parallelisms over Ordered Fields General Elation Switching Dual Parallelisms Transitivity p-Primitive Parallelisms Transitive t-Parallelisms Transitive Deficiency One Doubly Transitive Focal-Spreads Appendices Open Problems Geometry Background The Klein Quadric Major Theorems of Finite Groups The Diagram Bibliography Index vered by Pseudo-Reguli Flocks Regulus-Inducing Homology Groups Hyperbolic Fibrations and Partial Flocks j-Planes and Monomial Flocks Derivable Geometries Flocks of α-Cones Parallelisms of Quadric Sets Sharply k-Transitive Sets Transversals to Derivable Nets Partially Flag-Transitive Affine Planes Special Topics on Parallelisms Constructions of Parallelisms Regular Parallelisms Beutelspacher's Construction of Line Parallelisms Johnson Partial Parallelisms Parallelism-Inducing Groups Parallelism-Inducing Groups for Pappian Spreads Linear and Nearfield Parallelism-Inducing Groups General Parallelism-Inducing Groups Coset Switching Finite E-Switching Parallelisms over Ordered Fields General Elation Switching Dual Parallelisms Transitivity p-Primitive Parallelisms Transitive t-Parallelisms Transitive Deficiency One Doubly Transitive Focal-Spreads Appendices Open Problems Geometry Background The Klein Quadric Major Theorems of Finite Groups The Diagram Bibliography Index NG>Coset Switching Finite E-Switching Parallelisms over Ordered Fields General Elation Switching Dual Parallelisms Transitivity p-Primitive Parallelisms Transitive t-Parallelisms Transitive Deficiency One Doubly Transitive Focal-Spreads Appendices Open Problems Geometry Background The Klein Quadric Major Theorems of Finite Groups The Diagram Bibliography Index.