Kai , L., Taining , Y., & Chun , S. (2008). Записки Горного института, 174, 118-120. извлечено от https://pmi.spmi.ru/pmi/article/view/7501

Kai , L., Taining , Y., & Chun , S. (2008). Some topics on using ultrasonic method for concrete casting level measurement in bored pile foundation. Journal of Mining Institute, 174, 118-120. Retrieved from https://pmi.spmi.ru/pmi/article/view/7501