Development of the banknote began in the Tang Dynasty during the 7th century, with local issues of paper currency, although true paper money did not appear until the 11th century, during the Song Dynasty.
A contract typically does not have to be notarized. A notary public (or simply notary) provides an acknowledgment that the signature appearing on the document is that of the person whose signature it purports to be. There is a requirement that some documents be notarized, such as a real property deed.
If you want to do it yourself, state-specific contracts for deed are available for purchase online, or you can hire a lawyer to make sure everything is legally valid. In addition to the contract terms, the contract for deed must include your name and address, the seller's name and a legal description of the property. Sign the document, along with the seller, and have it notarized. Then file the document at the recorder's office for the county in which the property lies.