Versions of all the official publications of the Athenian Agora Excavations are available via the publications page of the American School of Classical Studies at Athens, and also via the Athenian Agora Excavations Project page.
Search for Items Inside The Athenian Agora 1, Portrait Sculpture, by E. B. Harrison, 1953, and so on, though volume 34 of the series.
Likewise with the Agora related Hesperia Supplements, you can
Search for Items Inside Prytaneis: A Study of the Inscriptions Honoring the Athenian Councillors, by Sterling Dow, 1937, as well as with seventeen additional Hesperia Supplements.
See also: Open Access Publications: Publications of the American School of Classical Studies at Athens