References :
1. Sikh Rahit Maryada, Amritsar, 1975
2. Kapur Singh, Parasaraprasna. Amritsar, 1989
3. Sher Singh, Giani, ed.. Thoughts on Forms and Symbols in Sikhism. Lahore, 1927
4. Uberoi, J.P.S., “The Five Symbols of Sikhism,” in Sikhism. Patiala, 1969
5. Nripinder Singh, The Sikh Moral Tradition. Delhi, 1990