Gimeno, Marta; Pamplona, Pablo; Gurría, Alejandro, eds. (2007). "Álvarez, Casta". Gran Enciclopedia Aragonesa (in Spanish). Archived from the original on 6 September 2016. Retrieved 11 September 2019.
historiaragon.com
Navascués Alcay, Santiago (29 May 2017). "Casta Álvarez Barceló". Historia de Aragón (in Spanish). Retrieved 22 May 2020.
web.archive.org
Gimeno, Marta; Pamplona, Pablo; Gurría, Alejandro, eds. (2007). "Álvarez, Casta". Gran Enciclopedia Aragonesa (in Spanish). Archived from the original on 6 September 2016. Retrieved 11 September 2019.
