Bootstrap 4 text sub sup

Example

blockquote {
  margin: 0 0 1rem;
}

b,
strong {
  font-weight: bolder;
}

small {
  font-size: 80%;
}

sub,
sup {
  position: relative;
  font-size: 75%;
  line-height: 0;
  vertical-align: baseline;
}

sub {
  bottom: -.25em;
}

sup {
  top: -.5em;
}