Whether ability to acquire a discovered object via its presence in one's territory is like establishing a proxy or is an extension of one's personal power of Acquisition: Bava Metzia 10b-11a
The object is acquired when it is in the hands of the finder: Bava Metzia 2a-b
A person who comes into money without effort, such as by finding something, should use some of it for a Mitzvah, such as acquiring a Torah or writing Tefillin, so that he will be able to retain the rest: Eruvin 64a-b
Two Claimants Holding the Item
Where two people hold the edges of an item, and both maintain that it is theirs in its entirety: Bava Metzia 2a, 7a
Above, where one claims its entirety and the other claims half: Bava Metzia 2a
If one asked the other to get the object for him: Bava Metzia 9b, 10a
Above, if the one who took it says "I got it for myself" After giving it to the one who asked him for it: Bava Metzia 9b-10a