1. Some piecewise polynomial alternatives to splines under tension;Nielson,1974
2. An interpolation curve using a spline in tension;Schweikert;J. Math. Physics,1966
3. Exponential and polynomial methods for applying tension to an interpolating spline curve;Barksy,1984
4. Scalar- and planar valued curve fitting using splines under tension;Cline;Comm. ACM,1974
5. Lyche, T ‘Exponential B-splines in tension’ to be published