Electronic reproduction. [S.l.] : HathiTrust Digital Library, 2010.
Master and use copy. Digital master created according to Benchmark for Faithful Digital Reproductions of Monographs and Serials, Version 1. Digital Library Federation, December 2002. http://purl.oclc.org/DLF/benchrepro0212
Issues for 1956- in Spanish, English or German; <1975-> Spanish, English or French; abstracts in English, Spanish and in the language of the text.
No. 1-30, 1956-71, in no. 31, 1972.
Description based on: Número 1 (30 setiembre 1956); title from PDF cover (publisher’s website, viewed Sept. 21, 2017).