There was a 1982 Pearse report, 1996 ARA Economic Value Study, the 1996 Altering Course — the Art May Inquiry, and finally in 1997 the Toy Process.
Ces différentes études sont le rapport Pearse, paru en 1982, la ARA Economic Value Study, de 1996, l'étude intitulée Altering Course — the Art May Inquiry, de 1996 et, enfin, le processus Toy, de 1997.