You will need
  • Mobile phone, album sheet, pen.
Sleep number, which processed the call to your phone number.
Open in your mobile phonebook " and the call of customer service.
Hearing the answer of the operator, enter the number consisting of 11 digits. You will not only get the initials of the caller of the phone owner, of course, if he wished to register your details. But you will be able to determine the mobile operator: MegaFon, Beeline, MTS or SMARTS.
The operator will answer your questions related to the phone number, including even the location of the subscriber in a given time, if you want. After the conversation, write down the initials of the owner, the address, if you recognized it and hit "cancel call".