Cruz, N. . H. (2002). Why is there only one Luzon grid?. IN As i see it [column]. Philippine Daily Inquirer.
Chicago-referens (17:e uppl.)Cruz, Neal H. "Why Is There Only One Luzon Grid?. IN As I See It [column]." Philippine Daily Inquirer 2002.
MLA-referens (9:e uppl.)Cruz, Neal H. "Why Is There Only One Luzon Grid?. IN As I See It [column]." Philippine Daily Inquirer, 2002.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.