Home›Browse›Hilbert's twenty-first problem🌐EnglishEnglishEspañolItalianoPortuguêsSvenskaРусский中文日本語EntityQ4155615· pop 7· linked from 35 articlesHilbert's twenty-first problemSign in to saveOn linear differential equations with certain propertiesAvailable in 7 languagesEspañol中文РусскийPortuguêsGreekSvenskavia Wikidata sitelinks · CC0