MEASUREMENTS OF FORMATION CONSTANTS OF[Na·18-Crown-6]+ AND[NH4·18-Crown-6]+ IN AQUEOUS SOLUTION BY 23Na AND 14N NMR METHOD
Mao Xian, Xu Guangzhi, Shen Qifeng, Lu Xiaoming, Liu Jun
Chinese Journal of Magnetic Resonance . 1986, (1): 9 -14 .