Divide spacing in bootstrap group of buttons - html

Question

How to get equal spacing in this group of buttons?
When I add pull-right to the class the search and plus buttons is set to below the search box.
<tr>
<th class="col-md-3">
<small>Firma</small>
<span class="glyphicon glyphicon-sort-by-alphabet glyph_sorting" aria-hidden="true"></span>
<span class="glyphicon glyphicon-sort-by-alphabet-alt glyph_sorting" aria-hidden="true"></span>
</th>
<th class="col-md-3"><small>Plaats</small></th>
<th class="col-md-3"><small>Telefoon</small></th>
<th class="col-md-3">
<form action="" method="post">
<div class="form-group col-xs-8">
<input type="text" class="form-control input-sm" placeholder="Search">
</div>
<button type="submit" class="btn btn-default btn-sm"><span class="glyphicon glyphicon-search" aria-hidden="true"></span></button>
<button type="button" class="btn btn-sm"><span class="glyphicon glyphicon-plus" aria-hidden="true"></span></button>
</form>
</th>
</tr>

Answer 1

Edit based on comment:
Set parent container (form) to flexbox row, and center it's children elements horizontally with even space in-between with justify-content:space-between & vertically with align-items:center.
Override bootstrap's .form-control's padding & margin, which is whats causing the space async between buttons & the search input.
form {
display: flex;
flex-flow: row wrap;
justify-content: space-between;
align-items: center;
}
div.form-group {
padding: 0;
margin: 0;
}
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<table>
<tr>
<th class="col-md-3">
<small>Firma</small>
<span class="glyphicon glyphicon-sort-by-alphabet glyph_sorting" aria-hidden="true"></span>
<span class="glyphicon glyphicon-sort-by-alphabet-alt glyph_sorting" aria-hidden="true"></span>
</th>
<th class="col-md-3"><small>Plaats</small></th>
<th class="col-md-3"><small>Telefoon</small></th>
<th class="col-md-3">
<form action="" method="post">
<div class="form-group col-xs-8">
<input type="text" class="form-control input-sm" placeholder="Search">
</div>
<button type="submit" class="btn btn-default btn-sm"><span class="glyphicon glyphicon-search" aria-hidden="true"></span></button>
<button type="button" class="btn btn-sm"><span class="glyphicon glyphicon-plus" aria-hidden="true"></span></button>
</form>
</th>
</tr>
</table>