Information circular / Department of Natural Resources, Maryland Geological Survey.

no.1 (1963); no.4-13 (1967-72); no.15-16 1971-1974; no.16 (1974); no.21 (1976); no.16-25 (1974-77); no.23-29 1977-1979; no.26-40 (1978-84); no.48 (1988); no.48-49 1988-1989; no.50 1989; no.51-52 1990-1991; v.40; v.10(1971); v.11(1971); v.12(1971); v.13(1972); v.14(1970); v.15(1971); v.22(1976); v.23(1977); v.24(1974); v.25(1975); v.26(1978); v.27(1978); v.3(1966); v.39(1984); v.41(1983); v.4(1967); v.42(1985); v.44(1985); v.45(1987); v.46(1986); v.47(1987); v.48(1988); v.49(1990); v.50(1991); v.51(1990); v.5(1967); v.52(1991); v.53(1996); v.6(1968); v.7(1969); v.8(1970); v.9(1970); v.19(1975); v.20(1976); v.18(1975); v.17(1974)