mySiteWithBootstrapAndBEM/css/fonts.css

@font-face {
   font-family: 'Open Sans Bold';
   src: url('../fonts/OpenSans-Bold.ttf')
}
@font-face {
   font-family: 'Open Sans Light';
   src: url('../fonts/OpenSans-Light.ttf')
}
@font-face {
   font-family: 'Open Sans Regular';
   src: url('../fonts/OpenSans-Regular.ttf')
}
@font-face {
   font-family: 'Open Sans Semibold';
   src: url('../fonts/OpenSans-Semibold.ttf')
}