The application of Statistical and Mathematical methods in Library andInformation Sciences is called Bibliometrics or Informetrics. The fundamen-tal topic in this area is the study of distributions which display regularityin scientific patterns, such as in the productivity of authors, or in articles,words or citations. In this study these distributions will be summarized anddiscussed after describing briefly the concept of Informetrics. Also an origi-nal applications will be given where the fit of the data to these distributionsis tested.