An excellent online resource that provides full runs of UFO magazines published in the US and 37 other countries is maintained by the Archives for the Unexplained in Sweden. Arranged by country, the listing supplies PDF files of hundreds of periodicals from the 1950s to the present.
Because the UFO phenomenon is international in scope, knowing about cases that take place in other regions of the globe offers a more comprehensive insight into its characteristics, variations, and social impact.