Uji toksisitas beberapa fraksi ekstrak etanol daun gynura procumbens (lour)merr terhadap larva udang Arthemia salina Lech.: Toxicity test- of some fractions of ethanolic extract of the leaves of Gynura procumbens (LOUR)M - Perpustakaan UGM, i-lib ([Yogyakarta] : Universitas Gadjah Mada, 1997)