Changes in trabecular bone, hematopoiesis and bone marrow vessels in aplastic anemia, primary osteoporosis, and old age: a comparative histomorphometric study. - Burkhardt,R.; Kettner,G.; Bohm,W.; Schmidmeier,M.; Schlag,R.; Frisch,B.; Mallmann,B.; Eisenmenger,W.; Gilg,T. (Bone, 1987)