California Code, Government Code - GOV § 53807

The certificates shall be sold by the board at their face value to the investing agency. Such certificates are a legal investment by the investing agency notwithstanding any provision of law limiting the investment which may be made by the investing agency. Payment of the purchase price of certificates may be made in accordance with mutual agreement between the investing agency and the board, which agreement may provide for such payment in installments as work upon the public building or buildings progresses and funds necessary therefor are required.