So in Wikipedia we have this. “In some cases, it may be important to distinguish between reversible and quasistatic processes. Reversible processes are always quasistatic, but the converse is not always true. For example, an infinitesimal compression of a gas in a cylinder where there is friction between the piston and the cylinder is a quasistatic,
but not reversible process.Although the system has been driven from its equilibrium state by only an infinitesimal amount, energy has been irreversibly lost to waste heat, due to friction.” But in the famous Russian book Sivuhin,2nd volume on page 95 of the Russian version it says that any quasi static process is reversible, because the reverse of any tiny change during 1-2 transition can be done during 2-1 transition. Who should I believe?)
