On Monday at noon, the literary review Bookforum tweeted out its own death notice: the current issue would regretfully “be the magazine’s last.” No other explanation was given for the sudden shuttering, but, the week before, it was announced that Bookforum’s parent publication, the monthly art-world bible Artforum, had been sold to Penske Media Corporation. Penske, or P.M.C., is a conglomerate that includes everything from Rolling Stone and The Hollywood Reporter to the art magazines ARTnews and Art in America.