diff --git a/morphology.bib b/morphology.bib
index 0201e36..a73cf92 100644
--- a/morphology.bib
+++ b/morphology.bib
@@ -1123,6 +1123,16 @@
 	doi = {10.1080/00437956.1954.11659524}
 }
 
+@InBook{hockett1963problem,
+	pages = {1-29},
+	publisher = {MIT Press},
+	editor = {Greenberg, Joseph H.},
+	booktitle = {Universals of Language},
+	author = {Hockett, Charles F.},
+	year = {1963},
+	title = {The problem of universals in language}
+}
+
 @Thesis{hoeksema1984categorial,
 	institution = {University of Groningen},
 	type = {PhD},