Injectivity of the Quotient h\g of two Morphisms and Ambiguity of Linear Grammars.

Paavo Turakainen Injectivity of the Quotient h\g of two Morphisms and Ambiguity of Linear Grammars. 91-96 2001 6 Journal of Automata, Languages and Combinatorics 1 db/journals/jalc/jalc6.html#Turakainen01