Any text is indebted to other texts, and there is nothing new in the space of intertextual meaning. Every text is inherently intertextual: it incorporates elements of other texts for a specific purpose. Intertextuality considers the text as a fabric or a network, a field where texts that come from very different discourses are crossed and ordered. On the surface of the scientific text the intertextuality has a set of markers that are also analyzed in the article that follows. The subject of the research is analysis of Spanish scientific articles and dissertations defended at the Faculty of Natural Sciences of the Autonomous University of Madrid (Spain). The methodological base of the research is leading to modern linguistics, discursive and communicative approaches. The topic of the investigation gets in line with trends in the development of modern linguistics in the context of a new scientific paradigm. The results demonstrate that in the academic discourse intertextuality is the universal principle to create a scientific text at the level of content since any text is retrospectively and prospectively linked to other research.