RefWorks has static IP addresses for RefWorks and the writing tool add-on. This allows institutions that enable IPs per application to enable only this set of IPs rather than the entire AWS IP range.
 

RefWorks, Write-n-Cite (WnC), APIs:

1. 75.2.82.25
2. 99.83.213.91
3. 75.2.27.14
4. 99.83.211.120
5. 23.251.253.212
6. Shibboleth – we recommended enabling these also if not using Single Sign On:
   52.223.14.21
   35.71.147.98

RefWorks Citation Manager (RCM):

1. 75.2.17.0
2. 99.83.183.105

RCM-Hangul:

1. 15.197.245.10
2. 3.33.248.82