Though published in 2010, the H.D. special issue of the Journal for Cultural and Religious Theory offers fascinating resources about H.D. and Robert Duncan, Sigmund Freud, the British Museum exhibits, spiritualism and the occult, and much more. The special issue, “H.D. and the Archaeology of Religion,” is introduced by Colbey Reid. Other articles are by Amy Evans, Lisa Simon, Erin M. McNellis, Amaranth Borsuk, and Merrill Cole.
A nice summary of the journal contents appears in H.D.’s Web: An E-newsletter, Winter 2009. Since the journal is indexed in religion and humanities databases, rather than ones devoted to literature, these citations may be hard to find.