https://books.google.fr/books?id=doInBwAAQBAJ&pg=PR4&lpg=PR4&dq=charles+walter+masters&source=bl&ots=JcspDyc7JO&sig=ACfU3U2ZDSfKwa9b9s-0nfXB4akULMWu3w&hl=fr&sa=X&ved=2ahUKEwi2grea9t_iAhUOUBoKHeMcDjIQ6AEwDnoECAkQAQ#v=onepage&q=charles%20walter%20masters&f=false
https://www.cambridgescholars.com/download/sample/61120
https://www.cambridgescholars.com/download/sample/61120