Bos, Len, Brudnyi, Alex, Levenberg, N. and Totik, V.. "Tangential Markov inequalities on transcendental curves". Constructive Approximation. An International Journal for Approximations and Expansions 19.3 (2003): 339-354. Print.
Bagby, T., Bos, Len and Levenberg, N.. "Multivariate simultaneous approximation". Constructive Approximation. An International Journal for Approximations and Expansions 18.4 (2002): 569-577. Print.