1. 4) SARJA A. Durability Design of Concrete Structures. 日本建築学会/材料施工委員会 特別講演. (1998)
2. 16) KAKUTA S. Evaluaiton of Very Early Age Concrete Using a Wave Propagation Method, Proceedings 14. RILEM Symposium on Quality Control of Concrete Structures. (1991) vol.167,
3. 17) SOSHIRODA T. Optimum testing age for nondestructive evaluation of concrete quality - Approach to earlier inspection-, Non-destructive Testing and Experimental Stress Analysis of Concrete Structures. Proceedings of the 7th International EXPERTCENTRUM Conference. (1998) p.42-47.
4. 21) ELVERY R. H. Ultrasonic Assessment of Concrete Strength at Early Ages. Magazine of Concrete Research. (1976) vol.28, no.97, p.181-190.