Amert, Susan, In a Shattered Mirror: The Later Poetry of Anna Akhmatova, Stanford University Press, 1992.

A book-length examination of the poetry that
Akhmatova produced in the 1950s and 1960s and the
ways in which her personal struggles may have influenced
it. Amert presents much of the poetry in
Russian alongside English translations.

Doherty, Justin, The Acmeist Movement in Russian Poetry, Oxford University Press, 1997.

The first major examination in English of the acmeist
movement, this book examines not only the three
principle figures (Akhmatova, Gumilyov, and Mandelshtam),
but also the minor poets who were their
followers.

Haight, Amanda, "1956-1966," in Akhmatova: A Poetic Pilgrimage, Oxford University Press, 1990, pp. 165-97.

Haight, a leading Akhmatova scholar, examines the
poet's later years and, in particular, possible
inspirations for "Midnight Verses."

Ivanov, Vyacheslav Vsevolodovich, "Meetings with Akhmatova," in Anna Akhmatova and Her Circle, compiled with notes by Konstantin Polivanov, translated from...