Mega Menu (edit)

https://www.megamenu.com/

https://pluginarchive.com/wordpress/megamenu

http://www.designerslib.com/bootstrap-mega-menu-templates/

https://designmodo.com/demo/css3megamenu/

http://designm.ag/inspiration/mega-menus/

https://code.tutsplus.com/tutorials/how-to-build-a-kick-butt-css3-mega-drop-down-menu--net-15129 (HAY)

More:

https://www.w3schools.com/howto/howto_css_mega_menu.asp

https://www.leotheme.com/guides/prestashop17/leo_megamenu/

https://www.jqueryscript.net/menu/Simple-jQuery-Drop-Down-Mega-Menu-Plugin-Mega-Menu.html

https://www.jqueryscript.net/demo/Creating-An-Accessible-Mega-Menu-with-jQuery-CSS3/

Responsive Menu

https://www.jqueryscript.net/menu/Mobile-friendly-Sliding-Mega-Menu-Plugin-jQuery.html

https://www.jqueryscript.net/menu/Lightweight-Pure-CSS-Mega-Menu-For-Bootstrap-Yamm.html (HAY)

https://www.jqueryscript.net/menu/Responsive-Cross-platform-jQuery-Mega-Menu-Plugin-megamenu-js.html

Dropdown Menu

https://css-tricks.com/solved-with-css-dropdown-menus/

http://jsfiddle.net/kkobayashi/y0tfuqxo/7/

https://www.bootply.com/testazoid/bThTHo2fgG (Dropdown open in right)

https://www.science-emergence.com/Articles/How-to-create-a-dropdown-menu-button-align-to-the-right-with-Bootstrap/

Bootstrap Grid 5 columns

https://codepen.io/DenisDov/pen/pyjpgP

https://www.uakron.edu/it/cms/responsive-guide/gridding/five-col.dot

http://jsfiddle.net/farnuehy/17/ (Tiếng Việt)

http://blog.dongiannhat.com/2016/04/chia-5-cot-trong-bootstrap.html (Tiếng Việt)

https://blog.polarbits.co/2014/02/16/quick-tips-5-column-layout-with-twitter-bootstrap/

https://stackoverflow.com/questions/31944691/bootstrap-5-column-layout

Dropdown & Table

Bootstrap table responsive with btn dropdown-menu wrapping within table (HAY)

https://codepen.io/imarun/pen/mPjZoo (HAY HAY HAY HAY HAY)

https://www.bootply.com/YvePJTDzI0 (HAY)

Responsive Data Table

https://css-tricks.com/responsive-data-table-roundup/

http://jsfiddle.net/D2RLR/6936/ (HAY)

Bootstrap Modal

https://bootstrapdocs.com/v3.3.4/docs/javascript/