SEARCH Articles Figures Tables Bonds to Sulphur, Phosphorus, Nitrogen and Halogens Four-membered Rings containing Sulphur, Nitrogen, and Phosphorus Phosphorus and Sulphur Phosphorus-Oxygen-Sulphur Compounds Phosphorus—Sulphur Links Sulphur-Nitrogen-Phosphorus Compounds The chlor-alkali, sulphur, nitrogen and phosphorus industries