According to the Journal Citation Reports, its 2009 impact factor is 3.292.

According to the Journal Citation Reports, it has a 2010 impact factor of 1.483.

The 2011 impact factor is 3.320 according to Journal Citation Reports.

According to the Journal Citation Reports, it has a 2009 impact factor of 1.868.

According to the Journal Citation Reports, its 2011 impact factor was 3.802.

According to the Journal Citation Reports, its 2008 impact factor is 1.581.

According to the Journal Citation Reports, its 2010 impact factor is 1.024.

According to the Journal Citation Reports, it has an impact factor of 1.326 for 2009.

According to the 2011 Journal Citation Reports, its impact factor is 3.090.

According to the Journal Citation Reports, it has a 2011 impact factor of 1.701.