Complex sentence: It publishes two primary research journals, MNRAS in astronomy and (in association with the Deutsche Geophysikalische Gesellschaft) GeoJI in geophysics, and A&G, which publishes review and other articles of wide interest in a'glossy' format.
Split into simpler sentences: It publishes two primary research journals, the Monthly Notices of the Royal Astronomical Society in astronomy and (in association with the Deutsche Geophysikalische Gesellschaft) the Geophysical Journal International in geophysics. It also publishes the magazine A&G which includes reviews and other articles of wide scientific interest in a'glossy' format.