أرسل هذا في رسالة قصيرة: Petrological, mineralogical, and geochemical compositions of coal in the Ombilin Basin, West Sumatra, Indonesia

__    __   _    _     _____      ___     __   _   
\ \\ / // | || | ||  /  ___||   / _ \\  | || | || 
 \ \/ //  | || | || | // __    | / \ || | '--' || 
  \  //   | \\_/ || | \\_\ ||  | \_/ || | .--. || 
   \//     \____//   \____//    \___//  |_|| |_|| 
    `       `---`     `---`     `---`   `-`  `-`