Perhaps you should try some spelling variations:
de covarianza » de varianza
covarianza 05 » carranza 05
abierta 1 » abierta y, abierta a, abierta 5
de marx » de mar, de marzo
marx a » marx la, marx y, marx una
a 1880 » a 1887, a 1850, a 1883
05 10 » 05 19, 06 10, 01 10
de a1 » de a, de al, de am
a1 de » 1 de, 11 de, a de
1 12 » 31 12, 1 2, 1 1

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( Cabildo abierta 1 12 de covarianza 05 10 ) OR ( Cabildo abierta de a1 de marx a 1880 ))~".
• Adding a wildcard symbol may retrieve word variants: (( Cabildo abierta 1 12 de covarianza 05 10 ) OR ( Cabildo abierta de a1 de marx a 1880 ))*.