The reference list includes over 700 entries, but citations are highly unevenly distributed, with 50% coming from just 17 sources. As illustrated in Figure 6, most frequently cited works are primary sources, with only four of the top-cited sources being secondary literature. This suggests the editors predominantly rely on materials contemporary to Bullinger’s time. A particularly notable case is Erasmus of Rotterdam, whose works (Adagia, LB, ASD) are cited across three different editions. When combined, Erasmus's works emerge as the most frequently cited, highlighting his significant influence on Bullinger and other reformers of the time.