A graph G is strongly regular if it is regular, not complete or empty and, given any two distinct vertices u and v in G, the number of vertices adjacent to both u and v only depends on whether u and v are adjacent or not. If G is strongly regular with n vertices, valency k, any pair of adjacent vertices have a common neighbours and any two distinct non-adjacent vertices have c common neighbours then we say G is an (n, k; a, c)-strongly regular graph.