Effects of long-term cryopreservation on hematopoietic progenitor cells in umbilical cord blood. - Mugishima,H.; Harada,K.; Chin,M.; Suzuki,T.; Takagi,K.; Hayakawa,S.; Sato,K.; Klein,J.P.; Gale,R.P. (Bone Marrow Transplant, 1999)