SIMBAD references

After the ``O-C'' technique is used to study the pulsation of the δ Scuti star VZ Cnc with the times of maximum light listed in the literature and a newly-determined time based on new photometry for this star, some high-quality photometry light curves in the literature are analysed by the Fourier decomposition, showing that there are more than 2 frequencies in the pulsation of this star, which might be one possible explanation of the existence of the large scatter in the ``O-C'' diagram.