I can’t even count how many times someone else has received credit for my work or for someone else’s. A lot of times they don’t even realize they are getting the credit for it. It is frustrating to see, but, most of the time, it doesn’t have any real long-term impact on me. When this happens we can be bitter and quit or just keep doing our job excellently. If you are working for “credit” only, you may want to reconsider what you are doing.