The purpose of this paper is to develop core books in Nigerian languages using citation analysis. A total of 449 theses and dissertations submitted to the Department of Linguistics and Nigerian Languages in six Nigerian universities from 1996 to 2007 constituted the population. The universities are University of Nigeria, Nsukka (UNN), University of Ife (OAU), University of Lagos (UNILAG), University of Ibadan (UI), Ahmadu Bello University, Zaria (ABU) and University of Benin (UNIBEN). A bibliometric study was conducted using indicators such as types of cited sources, most frequently cited books and the most frequently cited authors. A total of 27,686 bibliographic references were harvested from the theses with an average of 58.4 citations per theses. Books and monographs dominated the entire citations with 63.6%. Thirty-seven (37) most frequently cited books were identified. Top among these books are Chomsky’s Aspect of theory of syntax with 6.6% while the least was Sociolinguistics by P. Trudgill with (1.7%). Seventy-four (74) authors were identified as the most frequently cited. Noam Chomsky ranked first with 5.1% and the least was Okebalama, C.N with 0.7%. This study would be useful for language researchers and collection development of libraries particularly academic libraries where language research needs to be supported.