1. Hoff E.Language development.4th ed. [e book].USA :Wadsworth Publishing Company; 2009 .Available at:URL:http://www. CengageBrain. com:p.4-8.##
2. Paul R. Language disorders from infancy through adolescence: Assessment & intervention.5th ed. USA: Mosby Incorporated; 2007.P.4##
3. Astell AJ, Harley TA. Accessing semantic knowledge in dementia: evidence from a word definition task. Brain Lang. 2002;82(3):312-26. ##
4. Gaskell G. Oxford handbook of psycholinguistics. USA: Oxford University Press; 2007.P.198-202. ##
5. Murphy ML. Semantic relations and the lexicon.[ebook].USA: Cambridge University Press; 2003. Available at:URL:http://catdir.loc.gov.pdf:p.13. ##
6. Luria AR. Language and cognition[H.GHasemzadeh,trans]. Tehran: Arjmand Press; 1996.P.116-123. ##
7. Marinellie SA JC. Adjective definitions and the influence of word frequency. J Speech Lang Hear Res. 2003;46(5):1061. ##
8. Dockrell JE MD, George R, Ralli A. Beyond naming patterns in children with WFDs-definitions for nouns and verbs. J Neurolinguistics. 2003;16(2):191-211. ##
9. Marinellie SA, Johnson CJ. Definitional skill in school-age children with specific language impairment. J Commun Disord. 2002;35(3):241-59. ##
10. Al-Issa I. The development of word definition in children. J Genet Psychol. 1969;114(1):25-8. ##
11. Gavriilidou Z. The development of word definitions in Greek preschoolers[Internet]. Democritus University of Thrace.2008.Available at: URL:http://www.ling.ohio-state.edu/icgl/proceedings/9-Gavriilidou-Kedited-88.pdf :5-8. ##
12. Kikas E. The development of word definitions in children. J Russ East Eur Psychol. 1993;31(2):40-54. ##
13. Malekian M, Shirazi TS, Zarifian T, Rezasoltani P. Review and comparison of content growth in word definition of Persian speaking children with 4.5 to 7.5 years of age. Audiol. 2014;23(4):21-30. ##
14. Matloubi S, Zarifian T, Shirazi TS, Bakhshi E. Word Definitional Skills in School age Persian Speaking Children: A Developmental Study on Form. Iran Rehab J. 2015;13(3). ##
15. Johnson CJ, Anglin JM. Qualitative developments in the content and form of children's definitions. J Speech Hear Res. 1995;38(3):612. ##
16. To CKS, Stokes S, Man Y, T’sou B. An analysis of noun definition in Cantonese. Lang Speech. 2013;56(1):105-24. ##
17. Gutierrez-Cleflen VF, DeCurtis L. Word definition skills in Spanish-speaking children with language impairment. Commun Disord Q. 1999;21(1):23-31. ##
18. Shin MJ, Lee HR. Flexible Word Definition of School-Aged Children with Specific Language Impairment. Commun Sciences Disord. 2016;21(1):111-20. ##
19. Mohammadi M, Nilipoor R, Shirazi TS, Rahgozar M. Semantic differences of definitional skills between persian speaking children with specific language impairment and normal language developing children. J Rehab. 2011;12(2):48-55. ##
20. Benelli B, Belacchi C, Gini G, Lucangeli D. To define means to say what you know about things': The development of definitional skills as metalinguistic acquisition. J Child Lang. 2006;33(1):71. ##
21. Chau, Ching Sh,Water. The development of concrete noun and abstract noun definition[Undergraduate Thesis]. Pokfulam :The University of Hong Kong; 2001: 25-30##
22. Chan Y-L, Marinellie SA. Definitions of idioms in preadolescents, adolescents, and adults. J Psycholinguistic Res. 2008;37(1):1-20. ##
23. Snow CE, Cancino H, De Temple J, Schley S. Giving formal definitions: A linguistic or metalinguistic skill. Language processing in bilingual children. 1991.P.90-112. ##
24. Snow CE. The development of definitional skill. J Child Lang. 1990;17(3):697-710. ##
25. Marinellie SA JC. Definitional skill in school-age children with specific language impairment. J commun disord. 2002;35(3):59-241. ##
26. Johnson CJ AJ. Qualitative developments in the content and form of children's definitions. J Speech Lang Hear Res. 1995;38(3):612. ##
27.Rowe ML, editor Decontextualized Language Input and Preschoolers' Vocabulary Development. Seminars in speech and language; 2013: Thieme. ##
28.Marschark M, Convertino C, McEvoy C, Masteller A. Organization and use of the mental lexicon by deaf and hearing individuals. American annals of the deaf. 2004;149(1):51-61. ##
29.Belacchi C, Benelli B. (submitted) Ambergris is not a precious fossil: the development of definitional skills. Deve Psychol. 2005:5-10. ##
30.Walker SJ. Cognitive, Linguistic, and Social Aspects of Adults' Noun Definitions. J psycholinguist res. 2001;30(2):147-61. ##
31.Marinellie SA, Johnson CJ. Nouns and verbs: A comparison of definitional style. J psycholinguist res. 2004;33(3):217-35. ##
32.Skwarchuk S-L, Anglin JM. Expression of superordinates in children's word definitions. J Educ Psychol. 1997;89(2):298. ##
33.Marinellie SA, Chan Y-L. The effect of word frequency on noun and verb definitions: A developmental study. J Speech, Lang Hear Res. 2006;49(5):1001-21. ##
34.McGhee-Bidlack B. The development of noun definitions: A metalinguistic analysis. J Child Lang. 1991;18(02):417-34. ##
35.Doherty M, Perner J. Metalinguistic awareness and theory of mind: Just two words for the same thing? J Cogn Dev. 1998;13(3):279-305. ##
36.Marinellie SA, Johnson CJ. Adjective definitions and the influence of word frequency. J Speech, Lang Hear Res. 2003;46(5). ##
37.Benelli B, Arcuri L, Marchesini G. Cognitive and linguistic factors in the development of word definitions. J Child Lang. 1988;15(3):619-35. ##