Thomas, Abraham; Sharma, PK (1998). "The shift of ravi river and the geomorphological features along its course in Amritsar and Gurdaspur districts of punjab". Journal of the Indian Society of Remote Sensing. 26 (1–2): 57–68. Bibcode:1998JISRS..26...57T. doi:10.1007/BF03007340. S2CID140634479.
Thomas, Abraham; Sharma, PK (1998). "The shift of ravi river and the geomorphological features along its course in Amritsar and Gurdaspur districts of punjab". Journal of the Indian Society of Remote Sensing. 26 (1–2): 57–68. Bibcode:1998JISRS..26...57T. doi:10.1007/BF03007340. S2CID140634479.
Thomas, Abraham; Sharma, PK (1998). "The shift of ravi river and the geomorphological features along its course in Amritsar and Gurdaspur districts of punjab". Journal of the Indian Society of Remote Sensing. 26 (1–2): 57–68. Bibcode:1998JISRS..26...57T. doi:10.1007/BF03007340. S2CID140634479.