 Complete the following phrase:  In November 1936 he participated in the Villarreal offensive. In February and March 1937 Marcelino Bilbao fought with the Isaac Puente battalion in the siege of Oviedo, integrated into the 1st Brigade of the Basque Expeditionary Brigades. Faced with General Molas offensive, he participated in the withdrawal of the Guipuzcoan fronts, was a direct witness to the bombardment of Guernica and fought in the battle of Sollube. After the fall of the Bilbaos Iron Ring, it went to 