Handling Missing Data by Using Stored Truth Values.

http://doi.acm.org/10.1145/126482.126486 db/journals/sigmod/Gessert91.html G. H. Gessert Handling Missing Data by Using Stored Truth Values. 30-42 sigmodR/20-3/P030.pdf 1991 20 SIGMOD Record 3 db/journals/sigmod/sigmod20.html#Gessert91