Benjamin J. Song, Andrew H. Liu. “Metropolitan Endotoxin Exposure, Allergy and Asthma”. Current Opinion in Allergy and Clinical Immunology 3, № 5 (2003); J. E. Gereda et al. “Metropolitan Home Living Conditions Associated with Indoor Endotoxin Levels”. Journal of Allergy and Clinical Immunology 107, № 5 (2001).