Paper Chase is a research database designed to offer abstracts of research articles published in journals that have a highly rated impact factor as determined by ISI Impact Factor and PageRank. Abstracts are organized by date, with the most recently published papers listed first. 

Paper Chase

ON THE AMOUNT OF EXTERNAL MIRROR IMAGERY IN DOUBLE MONSTERS AND IDENTICAL TWINS.

Proc. Natl. Acad. Sci. U.S.A.. Nov 15, 1929;15(11):839-42.
Keeler CE.

Howe Laboratory, Harvard Medical School.