Attributes Not Appearing On Products page

I have set 4 attributes for my woocommerce store. While two of them appear on the front end, the other two are not visible. When I checked source code, the other two are visible but still not appearing on front end.

<div class="woocommerce-Tabs-panel woocommerce-Tabs-panel--additional_information panel entry-content wc-tab" id="tab-additional_information" role="tabpanel" aria-labelledby="tab-title-additional_information">
				
	<h2>Additional information</h2>

<table class="woocommerce-product-attributes shop_attributes">
			<tr class="woocommerce-product-attributes-item woocommerce-product-attributes-item--attribute_pa_format">
			<th class="woocommerce-product-attributes-item__label">Format</th>
			<td class="woocommerce-product-attributes-item__value"><p>Paperback</p>
</td>
		</tr>
			<tr class="woocommerce-product-attributes-item woocommerce-product-attributes-item--attribute_pa_condition">
			<th class="woocommerce-product-attributes-item__label">Book Condition</th>
			<td class="woocommerce-product-attributes-item__value"><p>New</p>
</td>
		</tr>
			<tr class="woocommerce-product-attributes-item woocommerce-product-attributes-item--attribute_pa_writer">
			<th class="woocommerce-product-attributes-item__label">Author</th>
			<td class="woocommerce-product-attributes-item__value"><p>Amish Tripathi</p>
</td>
		</tr>
			<tr class="woocommerce-product-attributes-item woocommerce-product-attributes-item--attribute_pa_cod">
			<th class="woocommerce-product-attributes-item__label">Cash on Delivery</th>
			<td class="woocommerce-product-attributes-item__value"><p>Yes</p>
</td>
		</tr>
	</table>
			</div>