Follow that which has been revealed upon you from Allah and do not follow any other friends besides it. Little do you recollect!.
[Surah Al-Araf: Ayah 3]

Was there anything revealed beside Quran or hadith?

Today I have completed your Deen.
[Surah Maida: Ayah 3]

This ayah was revealed on Prophet Muhammad (SallAllah-u-Alaihi-wa-Sallam), meaning Islam was completed in his time, was there anything besides Quran and Sunnah then?

Prophet Muhammad said (SallAllah-u-Alaihi-wa-Sallam): O people for sure, I am leaving among you these (two things, if you hold them firmly you would never go astray. Those two things are Allah’s book and the tradition/way of his prophet.
[Mustadrak Hakim, Sanad: Hassan]

The Prophet’s (SallAllah-u-Alaihi-Wa-Sallam’s) message is clear to his Ummah, he said of two Things (Quran & Sunnah), Not of three or four things.