Letter from Thomas Gold to Dr Yong-Bin Lee, College of Agriculture, Seoul National University, Nuweon City, Korea Thanks him for his letter of 27 July. Gold is sending him another article on the deep Earth methane issue, which is in the form of a question-and-answer paper. The purpose of it is to answer particular questions or problems that arise with this theory. Gold hopes he will find it helpful. Gold would be very interested to hear of any unusual sources of gas or oil that have been found in Korea. 18 September 1979