A libretto can be by a male.Logical formLearned from697 sentences. A libretto may pertain-to a male.Logical formLearned from410 sentences. A libretto can be by a male.Logical formLearned from222 sentences. Libretto can be by a male.Logical formLearned from197 sentences. A libretto can be by a female.Logical formLearned from126 sentences. A male may write a libretto.Logical formLearned from122 sentences. A libretto may be written/wrote by a male.Logical formLearned from80 sentences. A libretto can be for an opera.Logical formLearned from79 sentences. A libretto may pertain-to a female.Logical formLearned from74 sentences. A libretto may pertain-to a language.Logical formLearned from63 sentences. A person may write a libretto.Logical formLearned from61 sentences. A libretto may pertain-to an opera.Logical formLearned from55 sentences. Librettos may pertain-to a male.Logical formLearned from55 sentences. A libretto may pertain-to an opera.Logical formLearned from41 sentences. A female may write a libretto.Logical formLearned from41 sentences.