John Roddam Spencer Stanhope (English Wikipedia)

Gertrude is sometimes identified erroneously as the sister of John Roddam; she is in fact another niece, the eldest child of his brother, Sir Walter. See “New acquisitions at Cannon Hall Museum: Bronzes by Gertrude Spencer-Stanhope Barnsley,” Metropolitan Borough Council;^{[permanent dead link]} Charles Tiplady Pratt, A History of Cawthorne (Barnsley 1882), p.36; and article on Gertrude Spencer-Stanhope.

books.google.com

A.M.W. Stirling, A Painter of Dreams, p. 287; Bernard Burke, A Genealogical and Heraldic Dictionary of the Landed Gentry of Great Britain and Ireland (London 1863) part 2, 4th edition, p. 1417.
Sheila Kirk, “Philip Webb,” citing Grove Art Online; Caroline Dakers, Clouds” The Biography of a Country House (Yale University Press, 1993), p. 30; Henry-Russell Hitchcock, “High Victorian Gothic,” Victorian Studies 1 (1957), p. 54.
Caroline Dakers, The Holland Park Circle (Yale University Press), pp. 48–49.
Henry-Russell Hitchcock, Architecture: Nineteenth and Twentieth Centuries (Yale University Press, 1987), p. 359.
Obituary, The Annual Register: A Review of Public Events at Home and Abroad 1908 (London 1909), p. 133.
Gertrude is sometimes identified erroneously as the sister of John Roddam; she is in fact another niece, the eldest child of his brother, Sir Walter. See “New acquisitions at Cannon Hall Museum: Bronzes by Gertrude Spencer-Stanhope Barnsley,” Metropolitan Borough Council;^{[permanent dead link]} Charles Tiplady Pratt, A History of Cawthorne (Barnsley 1882), p.36; and article on Gertrude Spencer-Stanhope.
Royal Institute of Painters in Water Colours (Great Britain) (1884). A Catalogue of the 66th Exhibition. "Graphic" Office. p. 27.
New Gallery (London) (1888). The New Gallery 1889, an Illustrated Catalogue of the Summer Exhibition. p. 24.

Christie's, Fine Victorian Pictures, Drawings and Watercolours, catalogue of sale held on June 6, 1997, cited by Simon Poë, “Mythology and Symbolism in Two Works of Roddam Spencer Stanhope’s Maturity,” Journal of Pre-Raphaelite Studies 12 (2003) 35–61; Christie's auction catalogue Lot 43, Sale 5801 online and archived.

“About Evelyn De Morgan née Pickering,” The De Morgan Centre.
Susan P. Casteras, Colleen Denney et al., The Grosvenor Gallery: A Palace of Art in Victorian England (Yale University Press, 1996); “About Evelyn De Morgan née Pickering,” The De Morgan Centre.

Nic Peeters and Judy Oberhausen, “L’Arte della memoria: John Roddam Spencer Stanhope and the Tomb of His Daughter Mary,” from Marble Silence, Words on Stone: Florence’s English Cemetery, The City and the Book III International Conference 3–5 June 2004, online.

Sheila Kirk, “Philip Webb,” citing Grove Art Online; Caroline Dakers, Clouds” The Biography of a Country House (Yale University Press, 1993), p. 30; Henry-Russell Hitchcock, “High Victorian Gothic,” Victorian Studies 1 (1957), p. 54.

William Morris Gallery, “Morris & Co Hand Painted Tiles: Alcestis,” online exhibition. Archived 3 September 2007 at the Wayback Machine

Christie's, Fine Victorian Pictures, Drawings and Watercolours, catalogue of sale held on June 6, 1997, cited by Simon Poë, “Mythology and Symbolism in Two Works of Roddam Spencer Stanhope’s Maturity,” Journal of Pre-Raphaelite Studies 12 (2003) 35–61; Christie's auction catalogue Lot 43, Sale 5801 online and archived.
William Morris Gallery, “Morris & Co Hand Painted Tiles: Alcestis,” online exhibition. Archived 3 September 2007 at the Wayback Machine
ArtMagick Exhibition Listings Archived 2011-06-14 at the Wayback Machine, retrieved August 21, 2008.

Truth & beauty : the Pre-Raphaelites and the old masters. Melissa E. Buron, Susanna Avery-Quash, Fine Arts Museums of San Francisco. San Francisco. 2018. pp. 256–58. ISBN 978-3-7913-5728-7. OCLC 1019840657.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)
Truth & beauty : the Pre-Raphaelites and the old masters. Melissa E. Buron, Susanna Avery-Quash, Fine Arts Museums of San Francisco. San Francisco. 2018. p. 49. ISBN 978-3-7913-5728-7. OCLC 1019840657.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)

Truth & beauty : the Pre-Raphaelites and the old masters. Melissa E. Buron, Susanna Avery-Quash, Fine Arts Museums of San Francisco. San Francisco. 2018. pp. 256–58. ISBN 978-3-7913-5728-7. OCLC 1019840657.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)
Truth & beauty : the Pre-Raphaelites and the old masters. Melissa E. Buron, Susanna Avery-Quash, Fine Arts Museums of San Francisco. San Francisco. 2018. p. 49. ISBN 978-3-7913-5728-7. OCLC 1019840657.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)