[13] FHWA. Design pamphlet for the determination of layered elastic moduli for flexible pavement design in support of the 1993 AASHTO guide for the design of pavement structures, No FHWA-RD-97-077, Federal Highway Ad-ministration, 1997, p. 3. [En línea]. Disponible en: https://www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/97077/97077.pdf