•? S ANAS (W) PLATYRHYNCHOS
•            4510  ANAS
•            2866  PLATYRHYNCHOS
•      S3    2845  ANAS (W) PLATYRHYNCHOS
•?S S2 OR S3
•            2096  S2
•            2845  S3
•      S4    3515  S2 OR S3
•?S S1 AND S4
•             602  S1
•            3515  S4
•      S5      21  S1 AND S4
•?S S5/ENG
•      S6      13  S5/ENG
•?
Whoa Nellie!  What’s that “(W)” between the word “ANAS” and the word “PLATYRHYNCHOS”?  We’ll learn more about stuff like this later, but the WITH Operator “(W)” simply searches for two words that appear next to one another … in that order.  It’s a phrase search.

Set S4 basically covers the concept of mallards
Set S1 covered the concept of preening

Combining S1 and S4 with the AND Operator yielded 21 records … 13 of which are in English.  In BIOSIS Previews ®, the language limit for English works fine …