A reference can be to a program.Logical formLearned from66 sentences. A (reference service) can be online.Logical formLearned from66 sentences. A reference can be to a word.Logical formLearned from65 sentences. References may provide information.Logical formLearned from65 sentences. References can be to files.Logical formLearned from65 sentences. A person may understand a reference.Logical formLearned from65 sentences. References can be to sites.Logical formLearned from65 sentences. A reference can be to a line.Logical formLearned from65 sentences. A reference can be presidential.Logical formLearned from65 sentences. A (reference point) can be fixed.Logical formLearned from64 sentences. A reference can be to a writer.Logical formLearned from64 sentences. (Reference services) can be online.Logical formLearned from64 sentences. References can be fleeting.Logical formLearned from64 sentences. A reference can be to a world-city.Logical formLearned from64 sentences. A reference can be to a person.Logical formLearned from64 sentences.