I have still to try, but this code doesn’t seems to fit my aim, because I can’t repeat as many ‘book’ as they are for every author (I have many authors with a different quantity of books each one).
Maybe I re-write my example:
autor1, book1, ed, place, date
autor1, book2, ed, place, date
autor1, book3, ed, place, date
autor2, book1, ed, place, date
autor2, book2, ed, place, date
autor3, book1, ed, place, date
autor3, book2, ed, place, date
autor3, book3, ed, place, date
autor3, book4, ed, place, date
and I wish have:
author1
book1, ed, place, date
book2, ed, place, date
book3, ed, place, date
author2
book1, ed, place, date
book2, ed, place, date
author3
book1, ed, place, date
book2, ed, place, date
book3, ed, place, date
book3, ed, place, date
and so on… (with many different authors and different books for each one).