1.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org).

Franz Prince of Hatzfeldt Spouse: Clara Elizabeth HUNTINGTON Marriage: 28 Oct 1889, Kensington, London, England Source: patron submission

2.  Anon.  1915.  The Huntington Family in America: a Genealogical Memoir of the Known Descendants of Simon Huntington from 1633 to 1915.  Huntington Family Assn., Hartford, CT (online at GenealogyLibrary.com).  See excerpt.

3.  Biography: Collis Potter HUNTINGTON (online at the web site of the Huntington Family Association).

4.  Anon.  Sunday, 30 Apr 1905.  "Society at Home and Abroad."  New York Times, New York, NY, Part Four, Second Magazine Section, p. 1 (i.e., front page of society section; online at Ancestry.com; Image #21 of 47):

A story comes from London that the Countess Fabbricotti will open in that city a dressmaking establishment.  Such industries have been quite the fashion in London for some time, and there are many titled ladies who have embarked in various "trade" enterprises.  The Countess Fabbricotti was in New York in the Winter of 1903-1904.  She was the recipient of much attention and was a guest in the early Spring at several of the Aiken houses.  She is an attractive woman and is a native of Ireland.  Her marriage did not prove happy, and her income is limited.  She will be assisted, according to the same authority, by the Princess Hatzfeldt, who was Miss Clara Huntington, adopted daughter of the late Collis P. Huntington of this city.

5.  Anon.  21 October 1929.  "Out Town." [link died] Archives of the Sacramento Bee, Sacramento, CA (online at the Sacramento Bee web site):

The will of Clara Elizabeth von Hatzfeldt, a Sacramento grocer's daughter who became the adopted daughter of railroad magnate Collis P. Huntington and married a prince, is being challenged by relatives.

6.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).

7.  Image: Princess Francis Edmund von Hatzfeldt, née Clara Huntington.