a common occurrence

abnormal occurrence

Accident (Crash) Occurrence

aesthetic occurrence

air pollution occurrence

Analysis of reason of occurrence

annual earthquake occurrence rate

Anomalous occurrence

anticipated operational occurrence

any one occurrence

any one occurrence {= AOO

applied occurrence

appraisal of possibility of occurrence and harmfulness of geological disaster

area of grasshopper occurrence

area of probably occurrence

atmospheric pressure indexes of earthquake occurrence

attribute occurrence

average disaster occurrence

beginning occurrence stage

binding occurrence