Milky Way twin candidates according to the strict criteria. Panel a: index of the structural differences between galaxies and the Milky Way D_MR (Eq. (10)) as a function of the index of the evolutionary difference D_OH (Eq. (11)). The points are individual MaNGA (grey) and nearby (goldenrod) galaxies. The dashed lines indicate D_MR = 0.1 and D_OH = 0.1. Panel b: central oxygen abundance versus abundance at the optical radius. The galaxies with D_OH ≤ 0.1 (eMWAs) are marked with red crosses. The galaxies with D_MR < 0.1 (sMWAs) are indicated with blue plus signs. The green circle denotes the Milky Way. Panel c: optical radius versus stellar mass diagram. The notations are the same as in panel b. Panel d: optical radius versus rotation velocity diagram. The notations are the same as in panel b.