It's actually an A&R Cambridge - later Arcam - A60, rather than a Cambridge Audio, and it uses DIN input sockets rather than the phono sockets used on almost all modern amplifiers. You'll need a cable with a 3.5mm mini-jack plug on one end (for your laptop or iPhone), and a DIN plug on the other, wired with pin 3 for the left input, pin 5 for the right, and pin 2 for the common/return, as it says above the sockets on the rear of the amp.
This page gives some examples of suitable cables
- but note such cables are directional, in that different pins are used for input and output on the DIN plugs/sockets, so make sure you buy a cable wired up to take signal from the 3.5mm stereo plug to the DIN, and not vice versa.
The third cable on the page linked to above - the least expensive one - should be more than adequate for your needs. You can use any of the three DIN inputs on the amp for the connection.