W. Subodhi Karunaratne, Vijaya Kumar, Jan Pettersson and N. Savitri Kumar
Acta Agriculture Scandinavica Section B-Soil & Plant Science 58 ( 4 ): 345 - 351 , 2008
W. Subodhi Karunaratne, Vijaya Kumar, Jan Pettersson and N. Savitri Kumar
Acta Agriculture Scandinavica Section B-Soil & Plant Science 59 ( 4 ): 357 - 361 , 2009