KONÔPKA, Bohdan - TSUKAHARA, Hatsuo - NETSU, Akira. Development of needle retention in Japanese black pine (Pinus thunbergii Parl.) plantation in the years 1967-1997. In Ekológia : časopis pre ekologické problémy biosféry. - Slovak Academic Press : Bratislava. ISSN 1335-342X, 2000, vol. 19, no. 2, s. 141-150.