non-sampling error https://en.wikipedia.org/wiki/Non-sampling_error https://en.wikipedia.org/wiki/Non-sampling_error https://en.wikipedia.org/wiki/Non-sampling_error weblink https://en.wikipedia.org/wiki/Non-sampling_error https://en.wikipedia.org/wiki/Non-sampling_error Non Sampling Error https://en.wikipedia.org/wiki/Non-sampling_error