John Laird, Paul Rosenbloom and Allen Newell, Universal Subgoaling and Chunking: The Automatic Generation and Learning of Goal Hierarchies.

Jeff Shrager John Laird, Paul Rosenbloom and Allen Newell, Universal Subgoaling and Chunking: The Automatic Generation and Learning of Goal Hierarchies. 269-273 1987 32 Artif. Intell. 2 db/journals/ai/ai32.html#Shrager87