共 17 条
[1]
BUTTS C, 1918, KENTUCKY GEOL SURVEY, P63
[2]
BUTTS C, 1922, KENTUCKY GEOL SURVEY, P135
[3]
BUTTS C, 1918, KENTUCKY GEOL SURVEY, P46
[4]
BUTTS C, 1940, VIRGINIA GEOL SURVEY
[5]
BUTTS C, 1927, VIRGINIA GEOL SURVEY
[6]
GRABAU AW, 1910, N AM INDEX FOSSILS, V2, P522
[7]
Reger D. B, 1926, W VIRGINIA GEOL SURV
[8]
REGER DB, 1927, GEOL SOC AM BULL, V38, P397
[9]
REGER DB, 1926, W VIRGINIA GEOL SURV, P483
[10]
REGER DB, MERCER MONROE SUMMER, P204