We present a continuation of our investigation of the second most abundant isotopic species of nitrous oxide, (NNO)-N-14-N-15-O-16 and (NNO)-N-15-N-14-O-16, in the infrared (IR). Our two previous contributions looked at the 3500-9000 cm (1) region for (NNO)-N-14-N-15-O-16 and (NNO)-N-15-N-14-O-16, respectively, in the 3500-9000 cm (1) region. The use of highly enriched isotopologue samples in this study allowed us to go further into the IR, down to 1200 cm (1). A total of 2 2742 transitions have been assigned based on the effective Hamiltonian model, with 108 of them being reported here for the first time. Rovibrational analyses of 98, 101, 8, 3, 6, 1 and 1 bands for the (NNO)-N-14-N-15-O-16, (NNO)-N-15-N-14-O-16, (NNO)-N-15-N-15-O-16, (NNO)-N-14-N-15-O-18, (NNO)-N-15-N-14-O-18, (NNO)-N-14-N-15-O-17 and (NNO)-N-15-N-14-O-17 isotopologues, respectively, were also performed. (C) 2009 Elsevier Inc. All rights reserved.