1. Section 4, Construction; Vol. 04.08 Soil and rock; Building stones. Unconfined compression strength of cohesive soil;ASTM (American Society for Testing Materials),1987
2. Physical processes of fragipan formation;Bryant,1989
3. Fragipan formation in loess of the midwestem United States;Franzmeier,1989
4. Fragipan horizons in New York soils: II. Relationships between rigidity and particle size distribution;Grossman,1957
5. A rupture technique to determine fragipan strength;Hallmark,1979