| Mass murder -- Fiction. Matches 1 item |
| Mass murder -- Pennsylvania -- Nickel Mines -- Drama. Matches 1 item |
| Mass murder -- Pennsylvania -- Pittsburgh -- History -- 21st century. Matches 1 item |
| Mass murder -- Psychological aspects. Matches 1 item |
| Mass murder -- Soviet Union -- History. Matches 1 item |
| Mass murder -- United States. Matches 1 item |
| Mass murder -- United States -- Prevention. Matches 1 item |
| Mass murderers -- Case studies. Matches 1 item |
| Mass murderers -- Psychology. Matches 2 items |
| Mass (Music) -- 15th century. Matches 2 items |