Shrock, R. R. (1948). Sequence in Layered Rocks: A Story of Features and Structures Useful for Determining Top and Bottom or Order of Succesion in Bedded and Tabular Rock. New York: McGraw-Hill.

Shrock, Robert R. Sequence in Layered Rocks: A Story of Features and Structures Useful for Determining Top and Bottom or Order of Succesion in Bedded and Tabular Rock. New York: McGraw-Hill, 1948.

Shrock, Robert R. Sequence in Layered Rocks: A Story of Features and Structures Useful for Determining Top and Bottom or Order of Succesion in Bedded and Tabular Rock. New York: McGraw-Hill, 1948.