Hi Larry. I rarely rely on the offficial published Piano-Vocal sheet music when I learning new tunes. Having the chords, lyrics & listening to the original artist audio recording is usually a lot better for figuring out what to play as both chords & melody notes of official sheet are more often than not different than what is performed by the artist, in this case Dean Martin.
If you already have the Dean Martin rendition on CD to listen to (for the melody), then the lyrics & chords (simplied) linked here
should provide everything you'll need to play & sing it.
If you still want sheet music ($4.95) for it, go HERE