Lobert, M., Möller, H. E., Müller-Warmuth, W., Paulus, W., & Schöllhorn, R. (1989). Guest-host interactions in hydrated layered chalcogenides as studied by NMR chemical shift anisotropy. Synthetic Metals, 34(1-3), 659-663. doi:10.1016/0379-6779(89)90455-4.