Sunspot Catalogue of the Valencia Observatory (1920-1928)
  A sunspot catalogue was maintained by the Astronomical Observatory of Valencia University (Spain) from 1920 to 1928. Here we present a machine-readable version of this catalogue (OV catalog or OVc), including a quality control analysis. Sunspot number (total and hemispheric) and sunspot area series are constructed using this catalogue. The OV catalog's data are compared with other available solar data, demonstrating that the present contribution provides the scientific community with a reliable catalogue of sunspot data. 
V.M.S. Carrasco, J.M. Vaquero, A.J.P. Aparicio and M.C. Gallego
astro-ph.SR