AffinDB: a freely accessible database of affinities for protein-ligand complexes from the PDB. - Peter Block; Christoph A. Sotriffer; Ingo Dramburg; Gerhard Klebe (Nucleic Acids Res., 2006)

Secbase: Database Module To Retrieve Secondary Structure Elements with Ligand Binding Motifs. - Oliver Koch; Jason C. Cole; Peter Block; Gerhard Klebe (J. Chem. Inf. Model., 2009)