Recently I created ManyToMany relation using Composite Primary key and annotation as bi directional OneToMany . This code works flawless. Maybe it will help.
Since you are using @IdClass, the PricePK class need not be marked with the @Embeddable annotation. An example is given in http://www.java2s.com/Code/Java/JPA/SetIdClassforCompoundKey.htm.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.