we investigated the nature of the non-central shell-focusing singularity which can form during the collapse of a fluid [@coo]. It is easily shown that such a singularity is covered so long as the radial pressure is positive. By considering the case of a perfect fluid, we showed that negative pressure allows for a naked singularity if the ratio of the pressure to the density is $\leq -1/3$; and the singularity is covered if this ratio exceeds $-1/3$. We note that the weak energy condition allows for pressure to be negative, although it is questionable whether negative pressures could develop during the final stages of realistic stellar collapse. The BLK series solutions offer a promising avenue for investigating cosmic censorship, which deserves to be pursued further.

On physical grounds, imperfect fluids are more realistic than perfect ones; very little is known about their collapse properties though. An interesting paper is the one by Szekeres and Iyer [@si], who do not start by assuming an equation of state. Instead they assume the metric components to have a certain power-law form, and also assume that collapse of physically reasonable fluids can be described by such metrics. The singularities resulting in the evolution are 