Reference can be to legislation.Logical formLearned from24 sentences. Reference can be to a country.Logical formLearned from24 sentences. Reference can be to programs.Logical formLearned from24 sentences. A reference may pertain-to a scientist.Logical formLearned from24 sentences. (Reference sources) can be specialized.Logical formLearned from24 sentences. References can be between objects.Logical formLearned from24 sentences. Reference can be to requirements.Logical formLearned from24 sentences. Products may be offered by an author of a reference.Logical formLearned from24 sentences. References can be on a site.Logical formLearned from24 sentences. A material may be incorporated by reference.Logical formLearned from24 sentences. A library can be constituted-of-or-filled-with (reference materials).Logical formLearned from24 sentences. A reference can be to differences.Logical formLearned from24 sentences. Reference can be to processes.Logical formLearned from24 sentences. References can be to verses.Logical formLearned from24 sentences. A reference can be to extremists.Logical formLearned from24 sentences.