# Solar cycle 21

> Solar activity from 1976 to 1986

**Wikidata**: [Q7556138](https://www.wikidata.org/wiki/Q7556138)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Solar_cycle_21)  
**Source**: https://4ort.xyz/entity/solar-cycle-21


## References

1. Freebase Data Dumps. 2013