I'm confused as to where to look for the volume and issue number on this journal.
I am doing NLM citation
At the top of the article "Efficacy of Esomeprazole for Treatment of Poorly Controlled Asthma" is the following information: N Engl J Med 2009; 360:1487-1499
N Engl J Med=the abbreviated journal title
2009=the year of publication
360=the volume number; if there was an issue number, it would be next in ( )'s
1487-1499=the page numbers
I hope this helps! Let us know if you have any other questions--