What are the two major contributions of Saussure to Structuralism according to Rifkin and Ryan?

According to Rifkin and Ryan, Saussure's two major contributions to Structuralism are the concepts of the linguistic sign and the distinction between langue and parole. The linguistic sign comprises the signifier (the form of a Word or phrase) and the signified (the concept it represents), highlighting the arbitrary nature of language. Additionally, the distinction between langue (the underlying system and rules of a language) and parole (individual speech acts) emphasizes the importance of structure and systems in understanding language and meaning.