1. Nitrogen fixation by lichens and free-living microorganisms in deserts;Rychert,1978
2. Microbial populations of arid lands and their potential for restoration of deserts;Bashan,2010
3. Plants in Changing Environments;Bazzaz,1996
4. Factors influencing nitrogen fixation and nitrogen release in biological soil crusts;Belnap,2001
5. Microbes and microfauna associated with biological soil crusts;Belnap,2001