Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       particles
         hadrons - composite particles
           baryons - fermionic hadrons
             Sigma baryons - baryons with two u and/or d quarks (I=1)
               01.1 Sigma+ - positive Sigma
               01.2 Sigma0 - neutral Sigma
               01.3 Sigma- - negative Sigma
               02.1 Sigma(1385)+ - positive Sigma(1385)
               02.2 Sigma(1385)0 - neutral Sigma(1385)
               02.3 Sigma(1385)- - negative Sigma(1385)
               03.1 Sigma(1660)+
               03.2 Sigma(1660)0
               03.3 Sigma(1660)-
               04.1 Sigma(1670)+
               04.2 Sigma(1670)0
               04.3 Sigma(1670)-
               05.1 Sigma(1750)+
               05.2 Sigma(1750)0
               05.3 Sigma(1750)-
               06.1 Sigma(1775)+
               06.2 Sigma(1775)0
               06.3 Sigma(1775)-
               07.1 Sigma(1915)+
               07.2 Sigma(1915)0
               07.3 Sigma(1915)-
               08.1 Sigma(1940)+
               08.2 Sigma(1940)0
               08.3 Sigma(1940)-
               09.1 Sigma(2030)+
               09.2 Sigma(2030)0
               09.3 Sigma(2030)-
               10.1 Sigma(2250)+
               10.2 Sigma(2250)0
               10.3 Sigma(2250)-