Relationship between vitamin D in obstructive sleep apnea syndrome and psoriasis patients - Albayrak, Hülya; Fazlıoğlu, Nevin; Batar, Bahadır; Emin Yanık, Mehmet; Oran, Mustafa; Altıntaş, Nejat (Advances in Dermatology and Allergology/Postępy Dermatologii i Alergologii, 2022)