three.js/playground/fonts/open-sans/open-sans.css

/* open-sans-regular - cyrillic-ext_greek_greek-ext_cyrillic_latin_latin-ext_vietnamese */
@font-face {
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 400;
  src: local('Open Sans Regular'), local('OpenSans-Regular'),
       url('./open-sans-v15-cyrillic-ext_greek_greek-ext_cyrillic_latin_latin-ext_vietnamese-regular.woff2') format('woff2'), /* Chrome 26+, Opera 23+, Firefox 39+ */
       url('./open-sans-v15-cyrillic-ext_greek_greek-ext_cyrillic_latin_latin-ext_vietnamese-regular.woff') format('woff'); /* Chrome 6+, Firefox 3.6+, IE 9+, Safari 5.1+ */
}