Resources for PSPO 1/2 and PSM2
I wondered if anyone can recommend which books are best to read for self-learning the PSPO1, PSPO2 and PSM2 certifications. Or are all required?
As there are so many and its quite expensive to buy all of them.
Are there any other resources which may be useful? Like sample on-line exam questions.
Lastly is there somewhere they are able to be purchased second hand, I havent seen any on amazon or ebay.