APA

Arnold C. A., . (201935). On seedlike structures associated with Archaeopteris, from the Upper Devonian of northern Pennsylvania. Ann Arbor, Mich: Univ. of Michigan Press.

Chicago

Arnold Chester A, . 201935. On seedlike structures associated with Archaeopteris, from the Upper Devonian of northern Pennsylvania. Ann Arbor, Mich: Univ. of Michigan Press.

Harvard

Arnold C. A., . (201935). On seedlike structures associated with Archaeopteris, from the Upper Devonian of northern Pennsylvania. Ann Arbor, Mich: Univ. of Michigan Press.

MLA

Arnold Chester A, . On seedlike structures associated with Archaeopteris, from the Upper Devonian of northern Pennsylvania. Ann Arbor, Mich: Univ. of Michigan Press. 201935.