APA (7th ed.) Citation

Cassiers, N., Halleux, P., & Ruttiens, H. (1981). Speelgoed. Brussel: OIVO.

Chicago Style (17th ed.) Citation

Cassiers, N., P. Halleux, and Henri Ruttiens. Speelgoed. Brussel: OIVO, 1981.

MLA (8th ed.) Citation

Cassiers, N., et al. Speelgoed. Brussel: OIVO, 1981.