Bahague Jr., R., & 		Galapon, E.
(2007).
 Static Behaviors of Confined Time-Arrival Operators.
<em>Science Diliman: A Journal Of Pure And Applied Sciences, 15</em>(1).
Retrieved from <a href="https://www.journals.upd.edu.ph/index.php/sciencediliman/article/view/139" target="_new">https://www.journals.upd.edu.ph/index.php/sciencediliman/article/view/139</a>