EISS 11 follows the Unified style sheet for linguistics (from April 2007) for the style of reference lists. A local copy of this style sheet is available below, but you may also retrieve it from its original site. Note that the LaTeX style package for EISS 11 includes a BibTeX style file (due to Bridget Samuels) for the Unified style sheet for linguistics.
Unfortunately, the Unified style sheet for linguistics only regulates the style of reference lists, so for other questions of style (e.g., how to format linguistic examples or how to cite references in the main text), EISS 11 needs a complementary style sheet. For this purpose, EISS 11 follows the style sheet (from August 2013) of Linguistic Inquiry (LI), likewise provided below, but you may also download it from its original site.
The idea is that the LI style sheet provides the default style recommendations for everything except the style of reference lists, which is overridden by the Unified style sheet for linguistics (thus items 59–64 of the LI style sheet may be ignored). Note that the LI style sheet also contains some requirements that apply specifically to LI (e.g., items 1–2) that EISS 11 ignores. In general, though, EISS 11 does follow most of the style recommendations of the LI style sheet, but feel free to ask in the case of doubt about some particular item or items.
Download: Unified style sheet for linguistics | LI style sheet