APA

Richards H., Lamkin J., . (1970). Statistical and economic aspects of rail-highway grade crossing safety improvement programs in Texas. College Station, TX: Texas A&M University. Texas Transportation Institute. Research report nr 111-2.

Chicago

Richards HA, Lamkin JT, . 1970. Statistical and economic aspects of rail-highway grade crossing safety improvement programs in Texas. College Station, TX: Texas A&M University. Texas Transportation Institute. Research report nr 111-2.

Harvard

Richards H., Lamkin J., . (1970). Statistical and economic aspects of rail-highway grade crossing safety improvement programs in Texas. College Station, TX: Texas A&M University. Texas Transportation Institute. Research report nr 111-2.

MLA

Richards HA, Lamkin JT, . Statistical and economic aspects of rail-highway grade crossing safety improvement programs in Texas. College Station, TX: Texas A&M University. Texas Transportation Institute. Research report nr 111-2. 1970.