JPPPF Volume 5 Issue 1 contains seven articles.
Dear all authors and readers of JPPPF,
We apologize specifically Number 1 Year 2019 JPPPF published on 30 July 2019, because there are server upgrades and service improvements in the OJS system at the UNJ Journal portal. All articles completed from the publishing process will be online as soon as possible. Thank you for your understanding.