Bootstrap.txt

GENERAL     ->  https://getbootstrap.com/
                https://www.mrw.it/web-design/guida-bootstrap/
POPOVERS    ->  https://getbootstrap.com/docs/4.0/components/popovers/
                https://www.mrw.it/web-design/bootstrap-popover_11552.html
GRID SYSTEM ->  https://getbootstrap.com/docs/4.0/layout/grid/
IMAGES      ->  https://getbootstrap.com/docs/4.1/content/images/
TABLES      ->  https://getbootstrap.com/docs/4.0/content/tables/
MODALS      ->  https://getbootstrap.com/docs/4.0/components/modal/
                http://jsfiddle.net/n__o/19rhfnqm/
                https://stackoverflow.com/questions/14761942/bootstrap-tabs-inside-a-modal
                https://bootsnipp.com/snippets/2eyKg
COLLAPSE    ->  https://getbootstrap.com/docs/4.0/components/collapse/
COMPONENTS  ->  https://getbootstrap.com/docs/3.3/components/ 
FORMS       ->  https://getbootstrap.com/docs/4.0/components/forms/ 
INPUT       ->  https://getbootstrap.com/docs/4.0/components/input-group/