AFMPast exam papers

December 2015 and March 2016 were not published by ACCA maybe due to 4 sittings per year.

I am surprised that you are asking this, because the ACCA have made it very clear in their students newsletters (and on their website) that they are no longer publishing the exams for each separate sitting. Instead they are publishing hybrid papers two times a year. After the December exam they published a selection of questions (and answers) from the September and December exams. After the June exam they will publish a selection of questions from the March and June exams.

where can I access these hybrid papers

On the ACCA website (under 'student resources')