What can authors do for the papers they published in predatory journals?

What can authors do for the papers they published in predatory journals?
Pol Arch Med Wewn. 2016 Aug 9;
Authors: Dadkhah M, Darbani SM
PMID: 27510167 [PubMed - as supplied by publisher]

Source: Polskie Archiwum Medycyny Wewnetrznej - August 13, 2016 Category: Internal Medicine Tags: Pol Arch Med Wewn Source Type: research