I'm not opposed to doing the extra work but I thought maybe I could bill them for some minimum wage hours just for going back and taking the time to find all of the sources. That might be a reasonable compromise between my normal bill-able rate and the request that I do this for free - I guess it's my fault for not expanding my client base to the point where I can afford to risk losing them by making a fuss.
Would you try to push back a little bit and charge the client more? Or just take it on the chin and move on? Help!