MONOS: Multiplicity Of Northern O-type Spectroscopic systems. I. Project description and spectral classifications and visual multiplicity of previously known objects (Corrigendum)

Maíz Apellániz, J.;Trigueros Páez, E.;Negueruela, I.;Barbá, R. H.;Simón-Díaz, S.;Lorenzo, J.;Sota, A.;Gamen, R. C.;Fariña, C.;Salas, J.;Caballero, J. A.;Morrell, N. I.;Pellerin, A.;Alfaro, E. J.;Herrero, A.;Arias, J. I.;Marco, A.