19 The sons of Judah were Er and Onan: and Er and Onan died in the land of Canaan.
Numbers 26:19 Cross References - KJ2000
Genesis 38:1-10
1 And it came to pass at that time, that Judah went down from his brothers, and turned in to a certain Adullamite, whose name was Hirah.
2 And Judah saw there a daughter of a certain Canaanite, whose name was Shua; and he took her, and went in unto her.
3 And she conceived, and bore a son; and he called his name Er.
4 And she conceived again, and bore a son; and she called his name Onan.
5 And she yet again conceived, and bore a son; and called his name Shelah: and he was at Chezib, when she bore him.
6 And Judah took a wife for Er his firstborn, whose name was Tamar.
7 And Er, Judah's firstborn, was wicked in the sight of the LORD; and the LORD slew him.
8 And Judah said unto Onan, Go in unto your brother's wife, and marry her, and raise up descendants to your brother.
9 And Onan knew that the descendant would not be his; and it came to pass, when he went in unto his brother's wife, that he spilled it on the ground, lest that he should give a descendant to his brother.
10 And the thing which he did displeased the LORD: therefore he slew him also.
Genesis 46:12
12 And the sons of Judah; Er, and Onan, and Shelah, and Perez, and Zarah: but Er and Onan died in the land of Canaan. And the sons of Perez were Hezron and Hamul.
1 Chronicles 2:3-8
3 The sons of Judah; Er, and Onan, and Shelah: which three were born unto him of the daughter of Shua the Canaanitess. And Er, the firstborn of Judah, was evil in the sight of the LORD; and he slew him.
4 And Tamar his daughter-in-law bore him Perez and Zerah. All the sons of Judah were five.
5 The sons of Perez; Hezron, and Hamul.
6 And the sons of Zerah; Zimri, and Ethan, and Heman, and Calcol, and Dara: five of them in all.
7 And the sons of Carmi; Achar, the troubler of Israel, who transgressed in the devoted thing .
8 And the sons of Ethan; Azariah.