أرسل هذا في رسالة قصيرة: The compound equation related to the Bessel-Helmholtz equation and the Bessel-Klein-Gordon equation

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