Columbia subject headings:
Iqbal, Muhammad, Sir, 1877-1938--Religion.
Iqbal, Muhammad, Sir, 1877-1938. Asrār-i khūdī.
Harvard subject headings:
Iqbal, Muhammad, Sir, 1877-1938--Religion.
Iqbal, Muhammad, Sir, 1877-1938. Asrār-i khvudī.
Iqbal, Muhammad, Sir, 1877-1938. Asrār-i khūdī
Princeton subject headings: