R Ser

 mk (10)

 |ds/mss|           Spectral type            |     reference     |
 -----------------------------------------------------------------
 |  /   |Md                                  |1993yCat.3135....0C|
 |  /   |MS                                  |1988PASP..100.1084B|
 |  /   |M7e                                 |1974ApJS...28..271K|
 |  /   |M6e                                 |1974ApJS...28..271K|
 |  /   |M5e                                 |1974ApJS...28..271K|
 |  /   |M8e                                 |1966ApJS...13..333K|
 |  /   |M7ep                                |1966ApJS...13..333K|
 |  /   |M7-e                                |1966ApJS...13..333K|
 |  /   |M6.5e                               |1966ApJS...13..333K|
 |  /   |M7e                                 |1966ApJS...13..333K|