Busscher W., Lipiec J., Bauer P., Carter T.:
Improved root penetration of soil hard layers by a selected genotype. (2000 r.)
Communications in Soil Science and Plant Analysis
2000, 31, (19&20), 3089-3101
Busscher W., Lipiec J., Bauer P., Carter T.:
Root penetration of artificially compacted hard layers. (1997 r.)
Bibliotheca Fragmenta Agronomica
1997, 2A/97, 119-122