@misc{Helcel_Antoni_Zygmunt_(1808–1870)_Letter,
 author={Helcel, Antoni Zygmunt (1808–1870)},
 copyright={Jagiellonian University (edition)},
 howpublished={online},
 language={Polish},
 title={Letter from Antoni Z. Helcel in the case for termination of service contract},
 keywords={freedom of contract, termination of a purchase and sale agreement, resolutive condition, termination of obligation, statute of limitations for a claim of nullity of contract, statute of limitations for a claim of termination, judicial oath, official oath, restitutio in integrum},
}