Cannon, John, and Ralph Griffiths, The Oxford Illustrated History of the British Monarchy, Oxford University Press, 1988.

This comprehensive overview devotes approximately
fifty pages to Charles I, the Civil War, and the
Restoration.

Fowler, Alastair, Robert Herrick, Oxford University Press, 1980.

This lecture delivered to the British Academy examines
the overall design of Hesperides,

Herrick's volume
of verse, as well as Herrick's use of the erotic
and the natural in his work.

MacLeod, Malcolm, A Concordance to the Poems of Robert Herrick, Oxford University Press, 1936.

This book allows readers to locate every use of every
word found in Herrick's poetry; for example, a reader
could look up the word "rosebuds" and find the eight
lines in Herrick's poems where the word occurs. This
is a useful tool for examining the ways that Herrick
uses various words and symbols throughout his work.

Press, John, Robert Herrick, Longman Group...