 One year after "Sechs" was published, Die Tödliche Doris published a poster, where they announced having produced a completely independent, non-commercial record, "the first invisible record of the world", created in the head of listeners by playing the album "Unser Debüt" simultaneously with "Sechs".Thus, Die Tödliche Doris created an additional, invisible 5th album in between "Unser Debüt" (their fourth) and "Sechs" (the sixth).Discogs