One significant occurrence in the conceptual art of the early seventies of the 20th c. in former Yugoslavia was the Group of Six Authors (Mladen Stilinović, Sven Stilinović, Vlado Martek, Željko Jerman, Boris Demur, Fedor Vučemilović), which was active in Zagreb from 1975 to 1981. Its activity belongs to the time which inherited the markers of global changes which appeared in art during the 1960s. In this period, the focus on the perception of artworks changes, along with the artist-artwork-audience relation.

The group never published its manifesto, nor did it have a set programme, and the members' affinities in art were not the same in the beginning. However, they were equally interested in the relationship between society and art, the social position of the artist, as well as art which favoured the idea and thought process to a possible aesthetic quality. The members presented their diverse conceptual practices on exhibitions-actions.

Exhibitions-actions are installations of artworks, realisations of processes and performances which the group members orchestrated from 1975 to 1979. Exhibiting in the public space enabled the performing of an artwork in accordance to its need, or, the very act of performing the works in public constituted an autonomous work, at least by questioning the role of the artwork, public and public reaction, as well as their own position of an artist. The exhibitions-actions took place in Zagreb's public spaces - squares, street, swimming areas. With this, they made a "static" gallery into an event. This orientation towards the public was the primary definition and the common worldview of the Six. Their works and actions are also connected by the questioning of what is "public matters" - slogans, phrases, tautologies, sayings, common places, but in entirely different interpretations.

The other form of their joint work was the May 75 magazine. It was a "magazine as an artist book", and the first issue was published on 07/07/1978, and the final, seventeenth issue, on 16/01/1981. The concept for each issue was printed on the cover.

In a wider timespan and conceptual scope, the phenomenon of the Group of Six Authors and the consequences which come and relate from it (Podroom, The Expanded Media Space) is a part of the network of historical events which stem all the way from the early 1920s. This was the time when the Avant-garde publication Zenit by Ljubomir Micić, and Dada-Tank and Dada-Jazz of Dragan Aleksić were published in Zagreb when Josip Seissel/Jo Klek was active in the Zenit realm. Through an entire sequence of continuing occurrences (the EXAT 51 group, Gorgona group etc.), they continue that which is marked under the term "the Other Line".