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Published online by Cambridge University Press: 19 July 2016
We describe how the application of techniques which utilise all the information contained in multi-colour surveys of stellar-like objects can be employed to detect quasars over an extended redshift range. The method is particularly effective for the identification of quasars with redshifts z>2.2 where the application of the ultra-violet excess criterion breaks down. Spectroscopy of a small sample of objects from the first survey field has resulted in the detection of two new faint quasars with redshifts z=3.42 and z=4.01 (ref. 1).