Immunization status in chronic obstructive pulmonary disease: A multicenter study from Turkey oleh Tevfik Ozlu, Yilmaz Bulbul, Derya Aydin, Dursun Tatar, Tulin Kuyucu, Fatma Erboy, Handan Inonu Koseoglu, Ceyda Anar, Aysel Sunnetcioglu, Pinar Yildiz Gulhan, Unal Sahin, Aydanur Ekici, Serap Duru, Sevinc Sarinc Ulasli, Ercan Kurtipek, Sibel Gunay, RIMPACT Study Investigators