Update README.md

README.md

@@ -19,7 +19,7 @@ Vega is an AutoML algorithm tool chain developed by Noah's Ark Laboratory, the m
 | NAS | SR-EA | An Automatic Network Architecture Search Method for Super Resolution | [ref](./docs/en/algorithms/sr-ea.md) |
 | NAS | [ESR-EA: Efficient Residual Dense Block Search for Image Super-resolution](https://arxiv.org/abs/1909.11409) | Multi-objective image super-resolution based on network architecture search | [ref](./docs/en/algorithms/esr_ea.md) |
 | NAS | [Adelaide-EA: SEGMENTATION-Adelaide-EA-NAS](https://arxiv.org/abs/1810.10804) | Network Architecture Search Algorithm for Image Segmentation | [ref](./docs/en/algorithms/Segmentation-Adelaide-EA-NAS.md) |
-| NAS | SP-NAS: Serial-to-Parallel Backbone Search for Object Detection | Serial-to-Parallel Backbone Search for Object Detection Efficient Search Algorithm for Object Detection and Semantic Segmentation in Trunk Network Architecture | [ref](./docs/en/algorithms/sp-nas.md) |
+| NAS | [SP-NAS: Serial-to-Parallel Backbone Search for Object Detection](http://openaccess.thecvf.com/content_CVPR_2020/papers/Jiang_SP-NAS_Serial-to-Parallel_Backbone_Search_for_Object_Detection_CVPR_2020_paper.pdf) | Serial-to-Parallel Backbone Search for Object Detection Efficient Search Algorithm for Object Detection and Semantic Segmentation in Trunk Network Architecture | [ref](./docs/en/algorithms/sp-nas.md) |
 | NAS | Auto-Lane: CurveLane-NAS | An End-to-End Framework Search Algorithm for Lane Lines | Coming soon |
 | Model Compression | Quant-EA: Quantization based on Evolutionary Algorithm | Automatic mixed bit quantization algorithm, using evolutionary strategy to quantize each layer of the CNN network | [ref](./docs/en/algorithms/quant_ea.md) |
 | Model Compression | Prune-EA | Automatic channel pruning algorithm using evolutionary strategies | [ref](./docs/en/algorithms/prune_ea.md) |