Formation of unilateral contracts

Carlill v Carbolic Smoke Ball Co [1893] 1 QB 256, CA
http://www.bailii.org/ew/cases/EWCA/Civ/1892/1.html

Williams v Carwardine [1833] 5 C & P 566
http://www.bailii.org/ew/cases/EWHC/KB/1833/J44.html

R v Clarke [1927] 40 CLR 227
http://www.austlii.edu.au/au/cases/cth/HCA/1927/47.html

Errington v Errington and Woods [1952] 1 KB 290
http://www.bailii.org/ew/cases/EWCA/Civ/1951/2.html

Dahlia v Four Millbank Nominees Ltd [1978] Ch 231
http://www.bailii.org/ew/cases/EWCA/Civ/1977/5.html