The issues are #83, #84, #85, and #86. These comics were published in 1990 and feature a story arc known as "Earth War," which pits the team against the villain Llan the Sorcerer. The issues are from the first volume of the series, which ran from 1983 to 1994. The comics in the image are bagged and boarded, which is a common practice for collectors to preserve their condition.