ejb3-persistence.jar source

I have found the version 1.0.2 GA it here: http://grepcode.com/snapshot/repository.jboss.com/maven2/org.hibernate/ejb3-persistence/1.0.2.GA

I just did a search on http://www.mvnrepository.com for persistence api

http://mirrors.ibiblio.org/pub/mirrors/maven2/javax/persistence/persistence-api/1.0/persistence-api-1.0-sources.jar

also available in the java.net maven 1 repository http://download.java.net/maven/1/javax.persistence/java-sources/

for the implementations see hibernate entity manager, openjpa, eclipse toplink, glassfish persistence, ...