Journal articles:
McElveen, K. (2004). Children and Nature: Psychological, Sociocultural and Evolutionary Investigations. Edited by Peter H. Kahn, Jr. and Stephen R. Kellert. Cambridge: The MIT Press.
Pitman, C. (1970). The Spotted Sphinx, by Joy Adamson. New York: Collins.
Sacchi, S, et al. (2014). Moral reasoning and climate change mitigation: The deontological reaction toward the market-based approach. Amsterdam: Elsevier.
Books:
Shepherd, D. (2005). An Artist in Conservation. Cranleigh: R.D. & A.S. Shepherd Partnership.
Shepherd, D., & Howley, B. (2004). Painting with David Shepherd. New York: Collins.
Shepherd, D. (1975). The Man who Loves Giants: An Artist Among Elephants and Engines: David Shepherd’s Autobiography. Newton Abbot: David and Charles.
Newspapers:
https://www.thetimes.co.uk/article/david-shepherd-obituary-ghldd60k8
Websites:
https://www.davidshepherd.com/davidshepherd-paintings.html
http://mandyshepherd.com/index2.htm
https://alchetron.com/David-Shepherd-(artist)
Pictures:
https://davidshepherd.org/product/the-ivory-is-theirs/
https://davidshepherd.org/product/study-for-tiger-fire/
https://www.shippingtandy.com/features/union-castle-line-part-two/c
https://www.theguardian.com/artanddesign/2017/sep/21/david-shepherd-obituary?page=with%3Aimg-2
https://www.getsurrey.co.uk/news/surrey-news/world-famous-wildlife-artist-conservationist-13649210
https://www.amazon.com/artist-Africa-David-Shepherd/dp/0002110326
https://www.abebooks.co.uk/book-search/title/man-who-loves-giants/author/shepherd-david/
https://www.goodreads.com/book/show/3627481-a-brush-with-steam
https://www.amazon.co.uk/David-Shepherd-Man-His-Paintings/dp/0715387561
https://davidshepherd.org/product/an-artist-in-conservation/
https://davidshepherd.org/product/my-painting-life-book/
Other links:
http://www.artnet.com/artists/david-shepherd/