RT Journal Article SR Electronic T1 Peak expiratory flow rate variability in apparently healthy school children aged 10-15 years in Oredo, Nigeria JF Saudi Medical Journal JO Saudi Med J FD Prince Sultan Military Medical City SP 725 OP 725 VO 30 IS 5 A1 Mahmood D. Al-Mendalawi YR 2009 UL http://smj.org.sa/content/30/5/725.abstract