It was put on sale already in September 2014: A Thousand Forests in One Acorn, by Valerie Miles.
Some information by the publisher:
A Thousand Forests in One Acorn: An Anthology of Spanish-Language Fiction brings together twenty-eight of the most important Spanish-language writers of the twentieth century […] and provides them with a chance to discuss their careers and explain the aesthetic influences behind the pieces they chose to include in this volume. Unlike other anthologies, the stories and excerpts collected here were selected by the authors themselves and represent the “high point” of their writing career.
SOURCE: Open Letter Books