Zienkiewicz, O.
(2023).
 Trefftz type approximation and the generalized finite element method - history and development.
<em>Computer Assisted Methods In Engineering And Science, 4</em>(3-4), 305-316.
Retrieved from <a href="https://cames.ippt.gov.pl/index.php/cames/article/view/1374" target="_new">https://cames.ippt.gov.pl/index.php/cames/article/view/1374</a>