Following Erdős and Hajnal [12], a hypergraph (V, E) is said to have property B if it admits a proper two-coloring. Let m(n) denote the smallest number of edges in an n-uniform hypergraph that does not have property B, and \(m_v(n)\) the analogous number for an n-uniform hypergraph with \(|V|=v\) vertices. We give an overview of classical and recent bounds on m(n) and \(m_v(n)\) , respectively.