You cannot do much at all, but in most cases it will finally show up. I had a paper that was referenced five times in the different chapters (by different authors) of one and the same book, and this book was in some way confused by Google scholar algorithms with an earlier book in the same series (Part 1, part 2, etc) and which already was indexed. We tried to contact Google scholar but it kind of showed that they do not have any customer complaint department for this kind of issues. After a couple of months the citations all appeared. Improved algorithm perhaps, by machine learning.