In this reference system, "" is an abbreviation commonly used for Imperial or Imprenta (printing/press), and " 4 " typically denotes a specific volume or entry index. Based on the cataloguing style of the World List of Scientific Periodicals , this code points to:

Alternatively, it may refer to the series. Context of the World List

Could you clarify if you are looking for the indexed under this code, or a description of the periodical itself?

The World List was designed to standardize journal abbreviations to ensure each one indicates only one specific periodical. According to the Preface to the Second Edition , researchers were urged to use these exact codes to avoid confusion among more than cataloged.

publications (specifically technical communications or reports).