Revenues and accounts receivable from the Company's largest customers were as follows (in thousands):


	% of Total Revenue for the Three Months Ended June 30,		% of Total Revenue for the Six Months Ended June 30,		Accounts Receivable as of
Customer	2023	2022	2023	2022	June 30, 2023
A	36%	39%	33%	39%	$	10,776
B	22%	30%	24%	29%	$	35,184
C	14%	6%	11%	4%	$	21,104
D	13%	14%	17%	15%	$	22,518

Revenues from outside of North America represented approximately 98% and 97% for the three months ended June 30, 2023 and 2022, respectively, and 97% for both six-month periods ended June 30, 2023 and 2022. Revenues by geographic area are as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
Country	2023		2022		2023		2022
South Korea	$	82,029	$	79,096	$	148,089	$	168,783
China		57,520		51,180		114,947		106,580
Japan		1,509		1,392		3,156		2,445
Other non-U.S. locations		1,978		715		3,315		1,015
Total non-U.S. locations		143,036		132,383		269,507		278,823
United States		3,529		4,178		7,525		8,208
Total revenue	$	146,565	$	136,561	$	277,032	$	287,031

The Company attributes revenue to different geographic areas on the basis of the location of the customer.

Long-lived assets (net), by geographic area are as follows (in thousands):


	June 30, 2023		December 31, 2022
United States	$	117,196	$	117,255
Ireland		25,894		20,270
Other		14,476		5,920
Total long-lived assets	$	157,566	$	143,445

Substantially all chemical materials were purchased from one supplier. See Note 13 for further explanation.