Boolean (or some such) operators in CSS selector?

Hello, fellow Airtablans. I’m trying to set up a web clipper thingie that effectively serves as a story lead spreadsheet for interesting medical journal articles. One of the fields I want to pull is the date the study was published – info that appears differently, with different surrounding CSS/HTML, on each of the various journal sites I visit. I can set up a CSS selector for one of these sites, but when I tried to include two selectors separated by “OR,” it broke. Gratitude for any ideas!