odd formatting in bibliography: publisher location

Sometimes, for books, the bibliography creates a new line for the location of the publisher.  I can correct this by editing in the bibliography, but I can’t figure out why it is happening.  

I have tried re-typing the city name to be sure there is not an invisible character, but without success.  Any suggestions?  Thanks!

Are you sure there isn’t an extra line in the record following the the city name? 

I’ll check that when I am next at the computer.  Thanks very much!