BioStor
 | May 1st; Plants Appearing in Flower, in the Neighborhood of Philadelphia, from February to May (1860) Proceedings of The Academy of Natural Sciences of Philadelphia 12: 145-146 |
 | The insects of Betula in North America G Dimmock (1885) Psyche. Cambridge, Massachusetts 4: 271-286 |
 | Additions to the flora of Washington and vicinity, from April 1, 1884 to April 1, 1886 F H Knowlton (1886) Proceedings of The Biological Society of Washington 3: 106-132 |
 | New North American Fungi J B Ellis and Benjamin M Everhart (1890) Proceedings of The Academy of Natural Sciences of Philadelphia 42: 219-249 |