@misc{G._Paal_An,
 author={G. Paal},
 address={Երևան},
 howpublished={online},
 publisher={ՀՍՍՀ ԳԱ հրատ․},
 type={Հոդված},
 title={An angular-diameter-red-shift relation for rich clusters of galaxies},
 keywords={Astrophysics, Science, Galaxy},
}