Always take the time to double (or triple) check reference numbers and other citations details that are being manually transcribed. The best time to catch these mistakes is when the citation is being created or the source information is being manually copied. Recently while preparing to post an image to one of my Facebook groups, I inadvertently inserted the wrong image number into the citation.
It was only when going back to grab an additional detail about the photograph that I realized the error. Fortunately at that point in time correcting the error was easily done. Sometimes it is not so easy to catch the error when time has elapsed.
At least the image number was not buried under all the snow in the picture.