@article {1343, title = {The shoot apex of Callistophyton poroxyloides}, journal = {Contributions from the museum of paleontology, University of Michigan}, volume = {12}, year = {1956}, pages = {285-299}, chapter = {285}, url = {http://deepblue.lib.umich.edu/bitstream/2027.42/48300/2/ID140.pdf}, author = {Delevoryas, Theodore} }