JITENDRA KUMAR, RAJESH KUMAR, RATNA RAI, and D. S. MISHRA, “RESPONSE OF PANT PRABHAT GUAVA TREES TO FOLIAR SPRAYS OF ZINC, BORON, CALCIUM AND POTASSIUM AT DIFFERENT PLANT GROWTH STAGES”, The Bioscan, vol. 10, no. 2, pp. 495–498, Apr. 2015.