How to abbreviate Retro?

The ways to abbreviate Retro.

1
R.:
Retro(Roman, Latin)
8 years ago|137 views|share |citing 
APASmart Define. (2018). retro. Retrieved September 21, 2026, from http://smartdefine.org/retro/abbreviations/a
ChicagoSmart Define. 2018. "retro" http://smartdefine.org/retro/abbreviations/a (accessed September 21, 2026).
HarvardSmart Define 2018, retro, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/retro/abbreviations/a>.
MLASmart Define. "retro" 5 February 2018. Web. 21 September 2026. <http://smartdefine.org/retro/abbreviations/a>