MUSA, Daoud et al. Antitumor activity of an ethanol extract of Nigella sativa seeds. In Biologia. Section A. Section B. Section C, Botany. Zoology. Cellular and molecular biology. ISSN 0006-3088. ISSN 1335-6372. ISSN 1335-6380. ISSN 1335-6399. Bratislava : Slovak Academic Press, 2004, vol. 59, no. 6, p. 735-740.