Acquiring them via Money, Legal Bill, or Taking Hold of Them: Kiddushin 22b
Whether the son may buy them back, in place of the father: Kiddushin 17b
Whether the closest relative is the first in line for the obligation of buying it back: Kiddushin 21a-b
Buying them back halfway: Kiddushin 20b-21a
Whether one must borrow money to buy them back: Kiddushin 20b-21a
Whether relatives of the seller can force the buyer to sell it to them: Kiddushin 21a
Whether a relative must buy back the field if the seller could have done it himself, at the time of the original sale: Makkot 8a
Can't be Bought Back within 2 Harvests
Kohanim and Levites may always buy them back: Rosh HaShanah 29a [See Rashi]