Armstrong, E. C. R. (1913). Irish Seal-Matrices and seals: By E. C. R. Armstrong. Hodges & Figgis.
Lua i Stíl Chicago (17ú heag.)Armstrong, E. C. R. Irish Seal-Matrices and Seals: By E. C. R. Armstrong. Dublin: Hodges & Figgis, 1913.
Lua MLA (8ú heag.)Armstrong, E. C. R. Irish Seal-Matrices and Seals: By E. C. R. Armstrong. Hodges & Figgis, 1913.
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