With almost 1.9 million cumulative citations from 2008 to 2018, PNAS is the second most referenced scientific publication. PNAS has been labeled in the media as "prestigious," "sedating," "famous," and "high impact." However there are also criticisms that include expensive access, an exclusive focus on English-language papers, and an emphasis on quantitative studies over qualitative ones. Overall, PNAS is considered one of the most prestigious journals in science. It is accepted by scientists around the world as a source for new information in their fields of interest. Authors feel confident that their work will be read and cited by other scholars. In addition to receiving over 1.9 million unique visits per year, PNAS articles are also used by the U.S. government as a guide for policy decisions. The journal has a long-standing relationship with federal agencies such as the National Science Foundation and the Department of Energy. PNAS articles have also been used by agencies like NASA and the EPA as a basis for establishing research priorities or setting policy guidelines. Finally, PNAS articles are frequently cited by other researchers as evidence that their work is valid and should be taken into consideration when publishing new findings.