🌐EnglishEnglishDeutsch中文日本語EntityQ5500196· pop 5· linked from 17 articlesFree boundary problemType of partial differential equationAvailable in 5 languagesDeutsch中文日本語Catalanvia Wikidata sitelinks · CC0ConnectionsmathematicsEntityInternational Standard Book NumberEntityCategoriesBoundary value problemsPartial differential equations