Internet, http://lccn.loc.gov/n84804946, 2013-04-25
Information trouvée : Memoir of Augustus De Morgan, 1882 : (hdg.: De Morgan, Mrs. Sophia Elizabeth (Frend)
1809-1892; usage: Sophia Elizabeth De Morgan)
Memoir of Augustus de Morgan : with selections from his letters / by his wife Sophia
Elizabeth de Morgan, 1992 [reprod. de l'éd. de 1882]