@inbook {petkau2003optimal, title = {Optimal group sequential designs for the Anscombe-Colton model}, booktitle = {Mathematical Statistics and Applications: Festschrift for Constance van Eeden}, volume = {42}, year = {2003}, pages = {291{\textendash}315}, publisher = {IMS Lecture Notes - Monograph Series}, organization = {IMS Lecture Notes - Monograph Series}, author = {Petkau, A.John} }