A (case review) can be periodic.Logical formLearned from13 sentences. (Refresher courses) can be periodic.Logical formLearned from13 sentences. A program can be periodic.Logical formLearned from13 sentences. Patterns can be periodic.Logical formLearned from13 sentences. A reminder can be periodic.Logical formLearned from13 sentences. Dry spells can be periodic.Logical formLearned from13 sentences. Services can be periodic.Logical formLearned from13 sentences. An interrupt can be periodic.Logical formLearned from13 sentences. Antibiotics can be periodic.Logical formLearned from13 sentences. Periodic (limb movements) can be during sleep.Logical formLearned from13 sentences. (Report filings) can be periodic.Logical formLearned from13 sentences. An outbreak can be periodic.Logical formLearned from13 sentences. An error can be periodic.Logical formLearned from13 sentences. A periodic table can be extended.Logical formLearned from13 sentences. A chemical element can be in a periodic table.Logical formLearned from13 sentences.