Title 23, Chapter 2, Section 131
(a) The specific performance of a parol contract as to land shall be
decreed if the defendant admits the contract or if the contract has
been so far executed by the party seeking relief and at the instance
or by the inducements of the other party that if the contract were
abandoned he could not be restored to his former position.
(b) Full payment alone accepted by the vendor, or partial payment
accompanied with possession, or possession alone with valuable
improvements, if clearly proved in each case to have been done with
reference to the parol contract, shall be sufficient part
performance to justify a decree.