Sunan Abu Dawud
1707
Sahih+2

The aforesaid tradition has also been transmitted by Zaid bin Khalid al-Juhani through a different chain of narrators. This version has:The Messenger of Allah (SWAS) was asked about a find. He replied : Make the matter known for a year; if its owner comes, give it to him, otherwise note its string and its container and have it along with your property. If its owner comes, deliver it to him

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid