Permutation of Data Blocks in a Bubble Memory
A common internal organization of bubble memories consists of a set of (minor) 
loops, connected through another (major) loop.  The problem of obtaining any 
give n permutation of the minor loop contents in minimum time is studied
in this paper.  A lower bound to the number of steps required buy
a permutation algorithm is derived, and the class of optimum algorithms is 
identified.
CACM January, 1979
Bongiovanni, G.C.
Luccio, F.
