Far from my first song, but I bought this years ago:
Total waste as I (a) I can't read the music in it and anything I did learn I had to work out one note at a time. (b) I thought it would actually be a tutorial on slap, actually it doesn't contain a word of advice on how to play in thw style and (c) a large proportion of the songs aren't slap anyway...
I think it was a 'bandwagon jumping' exercise by the publisher and never intended as "an easy to follow insight into 'slap' bass playing".
The useful thing was it got me to listen to (but not play like) Stanley Clarke and Weather report!
<edit> Just looked up a review on Amazon " There are a couple of things I would like to point out though, which is firstly that it is not a book about slapping. Even most of the Mark King lines are his finger style tunes (Chinese Way, Dune Tune, Living it Up...). "
Bit late to ask for my money back...