Family Practice Notebook: Horner's Syndrome: The pathophysiology, causes and signs of horners syndrome.
Georgetown University School of Medicine: A clinical description of horner syndrome, with what lesions or injury it may occur and a brief definition of klympke dejerine syndrome.
Handbook of Ocular Disease Management - Horner's Syndrome: An article about the signs, symptoms, pathophysiology, management and clinical pearls.
NORD: Horner's Syndrome: Offer the synonyms, a general discussion and further resources.