An attack can be periodic.Logical formLearned from16 sentences. A disruption can be periodic.Logical formLearned from16 sentences. A flow can be periodic.Logical formLearned from15 sentences. Timers can be periodic.Logical formLearned from15 sentences. Variations can be periodic.Logical formLearned from15 sentences. Bills can be periodic.Logical formLearned from15 sentences. Flights can be periodic.Logical formLearned from15 sentences. A reinvestigation can be periodic.Logical formLearned from15 sentences. Snow can be periodic.Logical formLearned from15 sentences. Columns can be periodic.Logical formLearned from15 sentences. A submission can be periodic.Logical formLearned from15 sentences. A (peer review) can be periodic.Logical formLearned from15 sentences. A notice can be periodic.Logical formLearned from15 sentences. (Case reviews) can be periodic.Logical formLearned from15 sentences. Screenings can be periodic.Logical formLearned from15 sentences.