SIMBAD references

We observed a sample of 20 λ Bootis (LB) stars in three wavelength regions in the near infrared between 7600 and 10800A. We find that the Paschen lines correspond systematically to a spectral type which is later than the one attributed in the blue. By comparison with a convenient set of MK standard stars we find that the O, Ca, C, S and Si lines are weak in LB stars in varying degrees. An analysis of the 16 LB stars which we confirmed in the infrared shows that seven exhibit evidences of classical A-type shells in the spectroscopic sense. Of these seven, five are certain and two are dubious, giving thus a percentage of at least 30% of shells in LB stars.