Studies on Antitumour Cyclic Hexapeptides RA Obtained from Rubiae Radix, Rubiaceae (IV): Quantitative Determination of RA-VII and RA-V in Commercial Rubiae Radix and Collected Plants - Itokawa, Hideji; Takeya, Koichi; Mori, Noboru; Kidokoro, Shinpei; Yamamoto, Hiroo (Planta Medica, 1984)