The term "author groups" has been used throughout this exhibit because none of the pieces can be attributed, thus far, to any one specific author. Most of the pieces in the exhibit and in the larger collection are only marked by the name of the group - such as the Partido Comunista de España - that published it. Almost all of the author groups represented by the pieces in this exhibit were affiliated with or directly controlled by the Partido Comunista de España. Consequently, many of the handbills and broadsides include PCE as one of their author groups. Some items identify the author group more specifically by including the regional division of the PCE or the particular cell, which was responsible for publishing the piece. In addition to the PCE, another major author group includes the Juventudes Socialistas Unificadas (Unified Socialist Youth or J.S.U.), which, as the name indicates, was a group that targeted youths specifically. Finally, there are quite a few pieces that were produced by groups specifically targeted to women as well.
All of the author groups are listed here. This section of the site includes all of the pieces in the exhibit. Whereas other sections of the exhibit site group the pieces thematically, looking at all of the pieces from one author group together gives a sense of the range of themes and audiences that one organization tried to appeal to.