APA
Royal Institution of Chartered Surveyors, . (1981). The problem of disused mine shafts. One-day conference, Wednesday 2 December 1981. London: Surveyors` Technical Services.
Chicago
Royal Institution of Chartered Surveyors, . 1981. The problem of disused mine shafts. One-day conference, Wednesday 2 December 1981. London: Surveyors` Technical Services.
Harvard
Royal Institution of Chartered Surveyors, . (1981). The problem of disused mine shafts. One-day conference, Wednesday 2 December 1981. London: Surveyors` Technical Services.
MLA
Royal Institution of Chartered Surveyors, . The problem of disused mine shafts. One-day conference, Wednesday 2 December 1981. London: Surveyors` Technical Services. 1981.
