3 Demos of JavaScript / jQuery based sticky sidebar
jquery - Bootstrap`s sidebar with fixed footer and scrollable div - Stack Overflow
Basic Sidebar Navigation For Bootstrap 4 - Sider Menu | Free jQuery Plugins
Bootstrap Sidebar Tutorial - Step-by-step tutorial with 5 sidebar templates [updated in 2021]
Big dropdowns are unusable when used inside an `overflow:scroll` container, due to being constrained inside it · Issue #24251 · twbs/bootstrap · GitHub