por teléfono

= on the telephone, by tele(phone), over the phone, over the telephone

Ex. Telephone reference services have become problematic in recent years due to increased volume of patron demand, both in person and on the telephone.

Ex. If you are making your hotel reservations by phone, be sure to mention that you are with the VRD Conference in order to get the special rate.

Ex. The server will allow users to record voice messages over the phone.

Ex. She points to the fact that shoppers are quite happy to give credit card details over the telephone, with little or no security.

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= on the telephone, by tele(phone), over the phone, over the telephone

Ex: Telephone reference services have become problematic in recent years due to increased volume of patron demand, both in person and on the telephone.

Ex: If you are making your hotel reservations by phone, be sure to mention that you are with the VRD Conference in order to get the special rate.

Ex: The server will allow users to record voice messages over the phone.

Ex: She points to the fact that shoppers are quite happy to give credit card details over the telephone, with little or no security.