Perhaps you should try some spelling variations:
"pparticle swarms" » "particle swarms", "nparticle swarms", "particle storms", "ppparticle swarmss", "ppparticles swarms", "ppparticle swams"
"article swarm" » "particle swarms", "particles swarm", "particle swam"
"particle swarm" » "pparticle swarms", "pparticles swarm", "pparticle swam"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("article swarm") OR ((("particle swarm") OR ("pparticle swarms")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"article swarm\") or (((\"particle swarm\") OR (\"pparticle swarms\"))))".
• Removing quotes may allow a broader search: (( article swarm ) or ((( particle swarm ) OR ( pparticle swarms )))).
• Adding a wildcard symbol may retrieve word variants: (("article swarm") or ((("particle swarm") OR ("pparticle swarms"))))*.