I'm trying to modify in order to follow the author guidelines for advanced optical materials. I was able to change the citation style and the bibliography style but I still miss a feature of this journal. They say that:
"Where possible, composite references should be used; the individual parts should be
separated by a semicolon and labeled a), b), c), and not (a), (b), (c)."
 a) H. J. Ache, Angew. Chem. 1989, 101, 1; Angew. Chem. Int. Ed. Engl. 1989, 28,
1; b) H. Frey, Angew. Chem. 1998, 110, 2313; Angew. Chem. Int. Ed. 1998, 37, 2193;
c) G. M. Sheldrick, SHELXS-96, Program for the Solution of Crystal Structures,
University of Göttingen, Göttingen, Germany, 1996.
This means also that in the text the citation number (1) will be associated to the three articles.
How can I do this?