Anisotropic generalization of Buchdahl bound for specific stellar models Ranjan Sharma, Arpita Ghosh, Soumik Bhattacharya and Shyam Das Eur. Phys. J. C, 81 6 (2021) 527 Published online: 20 June 2021 DOI: 10.1140/epjc/s10052-021-09310-6