Cosmos sulphureus Cav. is more tolerant to lead than copper and chromium in hydroponics system

1. Aftab, N.
2. Saleem, K.
3. Khan, A.H.A.
4. Butt, T.A.
5. Mirza, C.R.
6. Hussain, J.
7. Farooq, G.
8. Tahir, A.
9. Yousaf, S.
10. Zafar, M.I.
11. Nawaz, I.
12. Iqbal, M.