Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 75. (Budapest 1983)

Kováts, D.: Distribution of internode lengths of two Lithospermum species (Boraginaceae)

Fig. 2. a-b. Distribution of internode lengths of three stoioniferous shoots of Lithospermum purpureocoendeum L. (curve S, with two maxima)