The journal TEMA has recently migrated to a new journal management system, and as a consequence, the publications since 2014 had problems in their DOI indexing numbers. These problemes were already identified and the maintenance staff are working on the solution. The problem should be completely solved in at most one month time. Thanks for your compreension on this matter.
Antonio Castelo Filho - Editor in Chief
Fabricio Simeoni de Sousa - Executive Journal
On behalf of editorial board.