callout matching for composite references

[elonzh]

Some journals require composite references when add citations, this will make grobid confused when callout matching.

Author Guidelines - Small - Wiley Online Library

Proceedings Volumes: [4] a) C. D'silva, V. Parthasarathy, S. N. Rao, in Proc. 2016 Workshop Wearable Systems Applications (Eds: E. H. Lee, A. L. Copley), ACM, New York 2016, 13; b) C. D’silva, presented at 14th Annual Int. Conf. Mobile Systems, Applications, Services, New York, June 2016.