ba4fde23558a0fa55b4fe0ff52cb83f6cdceed9812b7f8d020b33cbb54875dc4  62546/ciencia_a1926v1n4p146.pdf
b6b9b5dd7b08fe72d32bd60671a56f5f235aa032ac2337b4b403156510cd7344  62547/ciencia_a1926v1n6p261.pdf