SIMBAD references

A detailed reexamination of existing and new IUE low- and high-resolution spectra, plus a search of recent literature, shows that for most of the central stars of planetary nebulae the spectral classification previously called "continuous type" does not really exist. The stellar continua show primarily photospheric absorption features of N V, O V, C IV, H, He II, Fe VII, and Fe V, and/or P Cygni profiles.