 Suggestions for Further Reading: Adams 1986; Bourne 2006; Bigelow 1996; Emery 2020; Hinchliff 1996; Ingram 2016; Keller and Nelson 2001; Markosian 2004, 2013; McCall 1994; Rini and Cresswell 2012; Sider 1999, 2001; Sullivan 2012b; Tooley 1997; Zimmerman 1996, 1998.