Jeffrey,
The Tata link only gives a nominal composition, while the other link (to the Worldwide Guide of Equivalent Irons and Steels) gives the correct specification limits. For your purposes, you may want to invest in this book as the reference you were asking about as it give comprehensive international specs. If you are only dealing with UNS alloys and only need composition, you should consider investing in Metals and Alloys in the Unified Numbering System, available as SAE HS-1086 or ASTM DS-561 from these organizations.