Exactly as the title says. I figure that both branches would have the Qur'an in common, but I also recently learned that there are at least some Fiqhs that are Shia-only, and that implies at least some Fiqhs that are Sunni-only. So, what Islamic texts do the Sunni and Shia branches share? Which ones do they both recognize as authoritative?
They don't share any book. But they have some common hadiths especially if it concerns Imam Hasan,Hussien, and Ali (RA all), or major events in the life of the prophet Mohameed PBUH like the wars he participated in. But when it comes to jursiduction you can't find any book were the Sunni and Shia branches share
However, If you are talking about the Zaydi Shitte, then those shiite have a unique approach within Shitta Islamic thought that has similarities with Sunni Islam.
In matters of Islamic jurisprudence,
the Zaydis follow Zayd ibn ’Ali's teachings which are documented in his book Majmu’ al-Fiqh (Arabic: مجموع الفِقه). Zaydi fiqh is similar to the Hanafi school of Sunni Islamic jurisprudence.
Source: Article by Sayyid 'Ali ibn 'Ali Al-Zaidi, A short History of the Yemenite Shi‘ites (2005)
since Zaydism shares similar doctrines and jurisprudential opinions with Sunni scholars