Randomized Algorithms for Optimizing Large Join Queries. - Yannis E. Ioannidis; Younkyung Cha Kang (SIGMOD Conference, 1990)

Left-Deep vs. Bushy Trees: An Analysis of Strategy Spaces and its Implications for Query Optimization. - Yannis E. Ioannidis; Younkyung Cha Kang (SIGMOD Conference, 1991)

Randomized Algorithms for Query Optimization. - Younkyung Cha Kang (1991)