CARMA spectra of the HCN( J = 6→5), HCO ⁺( J = 6→5) (left), HNC( J = 6→5) (middle), and continuum emission at 2.76, 2.71, and 2.84 mm (left to right) toward APM 08279+5255 at a resolution of ~85 km s ⁻¹ (31.25 MHz). The velocity scales are relative to the tuning frequencies of 108.611 GHz (left) and 110.751 GHz (middle) and the central frequency of both LSBs at 105.391 GHz (right). The rms per velocity bin are 0.95, 0.88, and ~0.65–0.92 mJy (left to right). The solid curves show simultaneous Gaussian fits to the line and continuum emission where applicable.