I'm editing a document in which the author quotes from books & then puts his sources, but where there are more than one author sometimes he uses 'and' and sometimes '&', e.g. both 'Jones & Rotherham, 1988' and 'Fleabitten and Haugh, 1973' (NB not real authors.) I know that I have to decide on whether it's Jones & Rotherham or Jones and Rotherham, but is it OK to mix the two with different authors, as in the first example? It's US English, if that makes any difference. And life's too short for me to track down every book to find out what's written on the cover!
TIA for your advice.