Additionally, their distributions were different. People who read Dijkstra circa 1968 started using the phrase in their own publications within a decade, whereas people who read Viorst (or had it read to them) in 1972 and following years had at least a few decades of further delay before publishing anything using the corresponding phrase.
Additionally, their distributions were different. People who read Dijkstra circa 1968 started using the phrase in their own publications within a decade, whereas people who read Viorst (or had it read to them) in 1972 and following years had at least a few decades of further delay before publishing anything using the corresponding phrase.