The process for gaining charter approval in Massachusetts is nationally recognized as being extremely rigorous.

"We had to be extremely rigorous and very cautious," Dr. Moore said.

Security around the Embassy is extremely rigorous.

Most experts agree the new child care study, the largest of its kind ever conducted, is extremely rigorous.

Discipline in the army was extremely rigorous by modern standards, and the general had the power to summarily execute any soldier under his command.

Pasquet's training went through three stages-primary, basic, and advanced-and was extremely rigorous.

Gayhurst has a long record of success in such examinations which are extremely rigorous.

The empress developed extremely rigorous and disciplined exercise habits.

Their ideas were extremely rigorous, and placed tremendous emphasis on the long range influence of tonal materials.

Their instrumented testing is extremely rigorous compared with other automotive magazines.