Nature materials
Articles in SafetyLit 
 Y-Axis = Volume :: X-Axis = Issue 
?=unknown status :: X=no issue published :: nn=articles from issue :: A=relevant article(s) IDed to add
S=searched, nothing  relevant :: O=issue published but not yet searched :: C=combination issue
|  |  |  |  |  |  | 
| 3 (2004) | ? | ? | ? | ? | 1 | 
| 11 (2012) | ? | 1 | ? | 1 | ? | 
| 14 (2015) | ? | 2 | 1 | ? | 1 | 
| 15 (2015) | 1 | ? | ? | ? | ? |