complexity of transforming a propositional formula to its CNF

The space complexity of transforming a propositional formula to its CNF is as follows:

O(Var(p)*Leng(p))
where Var(p) is the number of variables, and Leng(p) is the length of the p.

According to

• Thierry Boy de la Tour: An Optimality Result for Clause Form Translation. J. Symb. Comput. 14(4): 283-302 (1992)

There are also linear algorihm proposed in

• Plaisted, D . A . and Greenbaum, S . (1986) . A structure-preserving clause form translation . Journal of Symbolic Computation, 2, 293-304.