Variations and Fugue on a Theme by Handel located. In other words, what gives unity to the variation set ... is not the theme as such, but rather a network of 'family resemblances', to use Wittgenstein's term, between the different variations." There are various opinions about the organization of the "Handel Variations". Hans Meyer, for example, sees the divisions as nos. 1–8 ('strict'), 9–12 ('free'), 13 ('synthesis'), 14–17 ('strict') and 18–25 ('free'), culminating, of course, in the fugue. William Horne emphasizes paired variations: nos. 3 and 4, 5 and 6, 7 and 8, 11 and 12, 13 and 14, 23 and 24. This helps him to group the
International Standard Book Number on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967, based upon the 9-digit Standard Book Numbering (SBN) created in 1966. The 10-digit ISBN format was developed by the International Organization for Standardization (ISO) and was published in 1970 as international standard ISO 2108 (the SBN code can be converted to a ten-digit ISBN by prefixing it with a zero digit "0"). Privately published books sometimes appear without an ISBN. The International ISBN agency sometimes assigns such books ISBNs on its own initiative. Another identifier, the International Standard Serial Number