APA (7th ed.) Citation

Koppenjan, S. Ninth International Conference on Ground Penetrating Radar. SPIE Digital Library.

Chicago Style (17th ed.) Citation

Koppenjan, Steven. Ninth International Conference on Ground Penetrating Radar. SPIE Digital Library.

MLA (9th ed.) Citation

Koppenjan, Steven. Ninth International Conference on Ground Penetrating Radar. SPIE Digital Library.

Warning: These citations may not always be 100% accurate.