أرسل هذا في رسالة قصيرة: Producing subharmonics on violin by means of three elements: Twisted strings, bow location and rosin amount / Tayebeh Kiumarsi 

  ______     ___     _    _     ______    _____   
 /_   _//   / _ \\  | |  | ||  /_   _//  |__  //  
 `-| |,-   | / \ || | |/\| ||   -| ||-     / //   
   | ||    | \_/ || |  /\  ||   _| ||_    / //__  
   |_||     \___//  |_// \_||  /_____//  /_____|| 
   `-`'     `---`   `-`   `-`  `-----`   `-----`