Hi!
First of all I want to say that this is not advertisement. I just want your advice how to prepare for PSPO 1 certification.
Unfortunatelly my first attempt was unsuccessfull (84%) and I think that just to know Scrum Guide is not enough to pass PSPO 1 exam. In this case I began to search for new source to learn more about PSPO and to try pass mock exam. So i've searched three sources. What do you think about them? Are they good enough to pay money or not?