1). Nonoccurrences
1). Nonoccurrence 2). Reoccurrences
1). Reoccurrence
1). Reoccurring 2). Occurrences
1). Occurrence 2). Occurrents 3). Reoccurred
1). Occurring 2). Occurrent
1). Occurred 2). Reoccurs
1). Reoccur
1). Occurs
1). Occur