I had a number of people ask for the vouchers. A couple did not follow the rules and were eliminated. There were six people that provided one or more links. I looked at the contents of each of the links and rated them based on how useful they would be for the exam. One link was for an article that was not about 12c and another was a duplicate of one provided by an earlier poster. These two were not counted at all. A number of links were perfectly valid articles about 12c... but on topics not covered by the 1Z0-052 exam. I gave these links half credit... worthwhile to read, but not part of a study program for the exam.
After evaluating all of this, the winners are:
+Bobin Varghese with four full-credit articles and one half-credit article.
+Henry FC with two full-credit articles and two half-credit articles.
+Андрей Басов1 with two full-credit articles.
+Yovanni Carpio with one full-credit articles and three half-credit articles.
+Daniele Pasian would have been fifth with one full-credit article. However, he won a voucher on Tim Hall's contest at Oracle-Base. Since he does not need another, the sixth-place entrant gets it.
+Hayde Castillo with three links on 12c (but none on exam topics) comes in sixth and squeaks in since Daniele has a voucher already.
For those of you that have won, use the 'Contact' page on my website to give me an email address to send the vouchers to.