1. The status of research on lignin;Adler;Z. Papier,1961
2. The biochemical formation of humic substances from lignin;Flaig,1958
3. The effects of humic substances on plant metabolism. Maataloustietellinen Aikakauskirja;Flaig;Z. Landwirtsch.-Wiss. Ges. Finland,1961
4. The conversion of lignin to humic substances;Flaig;Freiberger Forschungshefte,1962
5. Reactions with oxidizing enzymes from micro-organisms;Flaig;Planta Medica,1961