C. Galindo-Legaria, & A. Rosenthal. (1992). How to Extend a Conventional Optimizer to Handle One- and Two-Sided Outerjoin. Eighth International Conference on Data Engineering. https://doi.org/10.1109/ICDE.1992.213169

The paper started by identifying some use cases of 1- and 2-sided outerjoins. It seems like Dayal83 described a concept “subsumed tuples”, which is equivalent to the spurious tuples.