1. Mills, I.; Cvitas, T.; Homann, K.; Kallay, N.; Kuchitsu, K.Quantities,Units, and Symbols in Physical Chemistry; Blackwell Scientific Publications: Oxford, 1988. This reference lists the IUPAC's guidelines concerning thermochemical symbols, which we adopt. Instead of the more common expressions ΔGrxn 298(1), ΔHf 0°(R), or ΔHf 298°(RH), the use of ΔrxnG298(1), ΔfH0(R), or ΔfH298(RH) is recommended. See p 46.
2. Bond strengths of ethylene and acetylene