Newspapers, magazines, and journals of the era serve as rich primary sources for understanding the complexities of May '68. The UC Berkeley Library has in its collection a few of these such as L'enragé and Interluttes while others can be accessed online. The May Events Archive at Simon Fraser University with its digitized booklets, pamphlets, magazines, and newspapers from the epoch is one such place. Caroline Hoctan's Mai 68 en revues is an incredible reference tool for identifying journals and magazines.
Another strategy is to browse the more common publications such as Action poétique, Le contra social, Esprit, Les lettres nouvelles, La nouvelle critique, Le temps modernes, Opus International, La pensée, Tel Quel and others for the issues published that year.