TY - JOUR AU - Anthonisen, Nick R PY - 2009 DA - 1900/01/01 TI - Retrospective Studies SP - 704292 VL - 16 AB - SN - 1198-2241 UR - https://doi.org/10.1155/2009/704292 DO - 10.1155/2009/704292 JF - Canadian Respiratory Journal PB - Pulsus Group Inc KW - ER -